Merge branch 'master' into adsb_encoder

update api link
Merge branch 'master' of github.com:junzis/pyModeS
2020-05-04 01:53:27 +02:00 · 2020-05-04 01:51:33 +02:00 · 2020-05-04 01:09:40 +02:00 · 2020-05-04 01:07:02 +02:00 · 2020-05-04 00:56:36 +02:00 · 2020-05-04 00:11:29 +02:00
93 changed files with 1789 additions and 1156 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,9 @@ __pycache__/
 *.py[cod]
 .pytest_cache/

+#cython
+*.c
+
 # C extensions
 *.so

--- a/19
+++ b/19
@@ -0,0 +1,19 @@
+install:
+	pip install . --upgrade
+
+uninstall:
+	pip uninstall pyModeS -y
+
+ext:
+	python setup.py build_ext --inplace
+
+test:
+	python -m pytest tests
+
+clean:
+	find pyModeS/decoder -type f -name '*.c' -delete
+	find pyModeS/decoder -type f -name '*.so' -delete
+	find . | grep -E "(__pycache__|\.pyc|\.pyo$$)" | xargs rm -rf
+	rm -rf *.egg-info
+	rm -rf .pytest_cache
+	rm -rf build/*
--- a/README.rst
+++ b/README.rst
@@ -1,6 +1,42 @@
 The Python ADS-B/Mode-S Decoder
 ===============================

+PyModeS is a Python library designed to decode Mode-S (including ADS-B) message. It can be imported to your python project or used as a standalone tool to view and save live traffic data.
+
+This is a project created by Junzi Sun, who works at `TU Delft <https://www.tudelft.nl/en/>`_, `Aerospace Engineering Faculty <https://www.tudelft.nl/en/ae/>`_, `CNS/ATM research group <http://cs.lr.tudelft.nl/atm/>`_. It is supported by many `contributors <https://github.com/junzis/pyModeS/graphs/contributors>`_ from different institutions.
+
+Introduction
+------------
+
+pyModeS supports the decoding of following types of messages:
+
+- DF4 / DF20: Altitude code
+- DF5 / DF21: Identity code (squawk code)
+
+- DF17 / DF18: Automatic Dependent Surveillance-Broadcast (ADS-B)
+
+  - TC=1-4  / BDS 0,8: Aircraft identification and category
+  - TC=5-8  / BDS 0,6: Surface position
+  - TC=9-18 / BDS 0,5: Airborne position
+  - TC=19   / BDS 0,9: Airborne velocity
+  - TC=28   / BDS 6,1: Airborne status [to be implemented]
+  - TC=29   / BDS 6,2: Target state and status information [to be implemented]
+  - TC=31   / BDS 6,5: Aircraft operational status [to be implemented]
+
+- DF20 / DF21: Mode-S Comm-B messages
+
+  - BDS 1,0: Data link capability report
+  - BDS 1,7: Common usage GICB capability report
+  - BDS 2,0: Aircraft identification
+  - BDS 3,0: ACAS active resolution advisory
+  - BDS 4,0: Selected vertical intention
+  - BDS 4,4: Meteorological routine air report (experimental)
+  - BDS 4,5: Meteorological hazard report (experimental)
+  - BDS 5,0: Track and turn report
+  - BDS 6,0: Heading and speed report
+
+
+
 If you find this project useful for your research, please considering cite this tool as::

  @article{sun2019pymodes,
@@ -14,40 +50,6 @@ If you find this project useful for your research, please considering cite this



-Introduction
---------------------
-PyModeS is a Python library designed to decode Mode-S (including ADS-B) message. It can be imported to your python project or be used as a standalone tool to view and save live traffic data.
-
-Messages with following Downlink Formats (DF) are supported:
-
-**DF17 / DF18: Automatic Dependent Surveillance-Broadcast (ADS-B)**
-
- TC=1-4  / BDS 0,8: Aircraft identification and category
- TC=5-8  / BDS 0,6: Surface position
- TC=9-18 / BDS 0,5: Airborne position
- TC=19   / BDS 0,9: Airborne velocity
- TC=28   / BDS 6,1: Airborne status [to be implemented]
- TC=29   / BDS 6,2: Target state and status information [to be implemented]
- TC=31   / BDS 6,5: Aircraft operational status [to be implemented]
-
-
-**DF20 / DF21: Mode-S Comm-B replies**
-
- BDS 1,0: Data link capability report
- BDS 1,7: Common usage GICB capability report
- BDS 2,0: Aircraft identification
- BDS 3,0: ACAS active resolution advisory
- BDS 4,0: Selected vertical intention
- BDS 4,4: Meteorological routine air report (experimental)
- BDS 4,5: Meteorological hazard report (experimental)
- BDS 5,0: Track and turn report
- BDS 6,0: Heading and speed report
-
-
-**DF4 / DF20: Altitude code**
-
-**DF5 / DF21: Identity code (squawk code)**
-

 Resources
 -----------
@@ -55,32 +57,36 @@ Check out and contribute to this open-source project at:
 https://github.com/junzis/pyModeS

 Detailed manual on Mode-S decoding is published at:
-https://mode-s.org/decode.
+https://mode-s.org/decode

 The API documentation of pyModeS is at:
-http://pymodes.readthedocs.io
+https://mode-s.org/api



-Install
-------
-
-The pyModeS can be installed with extra option ``[all]`` in order to install dependencies ``pyzmq`` and ``pyrtlsdr`` automatically.
+Basic installation
+-------------------

 Installation examples::

-  # stable version, basic
+  # stable version
  pip install pyModeS

-  # stable version, including dependencies for streamer and rtlsdr
-  pip install pyModeS[all]
-
-  # development version, basic
+  # development version
  pip install git+https://github.com/junzis/pyModeS

-  # development version, including dependencies for streamer and rtlsdr
-  pip install git+https://github.com/junzis/pyModeS#egg=pyModeS[all]

+Dependencies ``numpy``, ``pyzmq`` and ``pyrtlsdr`` are installed automatically during previous installations processes.
+
+Advanced installation (using c modules)
+------------------------------------------
+
+If you want to make use of the (faster) c module, install ``pyModeS`` as follows::
+
+  git clone https://github.com/junzis/pyModeS
+  cd pyModeS
+  make ext
+  make install


 View live traffic (modeslive)
@@ -147,7 +153,7 @@ Common functions
  pms.hex2bin(str)      # Convert hexadecimal string to binary string
  pms.bin2int(str)      # Convert binary string to integer
  pms.hex2int(str)      # Convert hexadecimal string to integer
-  pms.gray2int(str)     # Convert grey code to interger
+  pms.gray2int(str)     # Convert grey code to integer


 Core functions for ADS-B decoding
@@ -161,7 +167,7 @@ Core functions for ADS-B decoding
  # Typecode 1-4
  pms.adsb.callsign(msg)

-  # Typecode 5-8 (surface), 9-18 (airborne, barometric height), and 9-18 (airborne, GNSS height)
+  # Typecode 5-8 (surface), 9-18 (airborne, barometric height), and 20-22 (airborne, GNSS height)
  pms.adsb.position(msg_even, msg_odd, t_even, t_odd, lat_ref=None, lon_ref=None)
  pms.adsb.airborne_position(msg_even, msg_odd, t_even, t_odd)
  pms.adsb.surface_position(msg_even, msg_odd, t_even, t_odd, lat_ref, lon_ref)
@@ -327,8 +333,19 @@ Here is an example:

 Unit test
 ---------
-To perform unit tests. First, install ``tox`` through pip. Then, run the following commands:
+To perform unit tests, ``pytest`` must be install first.

-.. code:: bash
+Build Cython extensions
+::

-  $ tox
+  $ make ext
+
+Run unit tests
+::
+
+  $ make test
+
+Clean build files
+::
+
+  $ make clean
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -17,5 +17,5 @@ help:
 # "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
 %: Makefile
 	rm -f source/pyModeS*.rst source/modules.rst
-	sphinx-apidoc -f -e -M -o source/ ../pyModeS
+	sphinx-apidoc -f -e -M -o source/ ../pyModeS  ../pyModeS/decoder/ehs.py ../pyModeS/decoder/els.py  ../pyModeS/streamer ../pyModeS/extra
 	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
--- a/doc/source/_templates/layout.html
+++ b/doc/source/_templates/layout.html
@@ -0,0 +1,17 @@
+{% extends "!layout.html" %}
+
+{% block footer %}
+{{ super() }}
+
+<!-- Global site tag (gtag.js) - Google Analytics -->
+<script async src="https://www.googletagmanager.com/gtag/js?id=UA-74700456-1"></script>
+<script>
+  window.dataLayer = window.dataLayer || [];
+  function gtag(){dataLayer.push(arguments);}
+  gtag('js', new Date());
+
+  gtag('config', 'UA-74700456-1');
+</script>
+
+
+{% endblock %}
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -14,19 +14,20 @@
 #
 import os
 import sys
-sys.path.insert(0, os.path.abspath('../..'))
+
+sys.path.insert(0, os.path.abspath("../.."))


 # -- Project information -----------------------------------------------------

-project = 'pyModeS'
-copyright = '2019, Junzi Sun'
-author = 'Junzi Sun'
+project = "pyModeS"
+copyright = "2019, Junzi Sun"
+author = "Junzi Sun"

 # The short X.Y version
-version = ''
+version = ""
 # The full version, including alpha/beta/rc tags
-release = ''
+release = ""


 # -- General configuration ---------------------------------------------------
@@ -39,26 +40,24 @@ release = ''
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
 extensions = [
-    'sphinx.ext.autodoc',
-    'sphinx.ext.todo',
-    'sphinx.ext.coverage',
-    'sphinx.ext.mathjax',
-    'sphinx.ext.viewcode',
-    'sphinx.ext.githubpages',
-    'sphinx.ext.napoleon',
+    "sphinx.ext.autodoc",
+    "sphinx.ext.mathjax",
+    "sphinx.ext.viewcode",
+    "sphinx.ext.githubpages",
+    "sphinx.ext.napoleon",
 ]

 # Add any paths that contain templates here, relative to this directory.
-# templates_path = ['']
+templates_path = ["_templates"]

 # The suffix(es) of source filenames.
 # You can specify multiple suffix as a list of string:
 #
 # source_suffix = ['.rst', '.md']
-source_suffix = '.rst'
+source_suffix = ".rst"

 # The master toctree document.
-master_doc = 'index'
+master_doc = "index"

 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
@@ -82,6 +81,10 @@ pygments_style = None
 # a list of builtin themes.
 #
 # html_theme = 'alabaster'
+html_theme = "neo_rtd_theme"
+import sphinx_theme
+
+html_theme_path = [sphinx_theme.get_html_theme_path()]

 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
@@ -108,7 +111,7 @@ pygments_style = None
 # -- Options for HTMLHelp output ---------------------------------------------

 # Output file base name for HTML help builder.
-htmlhelp_basename = 'pyModeSdoc'
+htmlhelp_basename = "pyModeSdoc"


 # -- Options for LaTeX output ------------------------------------------------
@@ -117,15 +120,12 @@ latex_elements = {
    # The paper size ('letterpaper' or 'a4paper').
    #
    # 'papersize': 'letterpaper',
-
    # The font size ('10pt', '11pt' or '12pt').
    #
    # 'pointsize': '10pt',
-
    # Additional stuff for the LaTeX preamble.
    #
    # 'preamble': '',
-
    # Latex figure (float) alignment
    #
    # 'figure_align': 'htbp',
@@ -135,8 +135,7 @@ latex_elements = {
 # (source start file, target name, title,
 #  author, documentclass [howto, manual, or own class]).
 latex_documents = [
-    (master_doc, 'pyModeS.tex', 'pyModeS Documentation',
-     'Junzi Sun', 'manual'),
+    (master_doc, "pyModeS.tex", "pyModeS Documentation", "Junzi Sun", "manual")
 ]


@@ -144,10 +143,7 @@ latex_documents = [

 # One entry per manual page. List of tuples
 # (source start file, name, description, authors, manual section).
-man_pages = [
-    (master_doc, 'pymodes', 'pyModeS Documentation',
-     [author], 1)
-]
+man_pages = [(master_doc, "pymodes", "pyModeS Documentation", [author], 1)]


 # -- Options for Texinfo output ----------------------------------------------
@@ -156,9 +152,15 @@ man_pages = [
 # (source start file, target name, title, author,
 #  dir menu entry, description, category)
 texinfo_documents = [
-    (master_doc, 'pyModeS', 'pyModeS Documentation',
-     author, 'pyModeS', 'One line description of project.',
-     'Miscellaneous'),
+    (
+        master_doc,
+        "pyModeS",
+        "pyModeS Documentation",
+        author,
+        "pyModeS",
+        "One line description of project.",
+        "Miscellaneous",
+    )
 ]


@@ -177,7 +179,7 @@ epub_title = project
 # epub_uid = ''

 # A list of files that should not be packed into the epub file.
-epub_exclude_files = ['search.html']
+epub_exclude_files = ["search.html"]


 # -- Extension configuration -------------------------------------------------
--- a/doc/source/index.rst
+++ b/doc/source/index.rst
@@ -9,11 +9,49 @@ Welcome to pyModeS documentation!
 The source code can be found at: https://github.com/junzis/pyModeS

 .. toctree::
-   :maxdepth: 3
+  :caption: Core modules
+  :maxdepth: 2
+
+  pyModeS.decoder.adsb
+  pyModeS.decoder.commb
+
+
+.. toctree::
+  :caption: ADS-B messages
+  :maxdepth: 2
+
+  pyModeS.decoder.bds.bds05
+  pyModeS.decoder.bds.bds06
+  pyModeS.decoder.bds.bds08
+  pyModeS.decoder.bds.bds09
+
+
+.. toctree::
+  :caption: ELS - elementary surveillance
+  :maxdepth: 2
+
+  pyModeS.decoder.bds.bds10
+  pyModeS.decoder.bds.bds17
+  pyModeS.decoder.bds.bds20
+  pyModeS.decoder.bds.bds30
+
+
+.. toctree::
+  :caption: EHS - enhanced surveillance
+  :maxdepth: 2
+
+  pyModeS.decoder.bds.bds40
+  pyModeS.decoder.bds.bds50
+  pyModeS.decoder.bds.bds60
+
+
+.. toctree::
+  :caption: MRAR / MHR
+  :maxdepth: 2
+
+  pyModeS.decoder.bds.bds44
+  pyModeS.decoder.bds.bds45

-   pyModeS.decoder
-   pyModeS.streamer
-   pyModeS.extra


 ----
--- a/doc/source/make.bat
+++ b/doc/source/make.bat
@@ -1,35 +0,0 @@
-@ECHO OFF
-
-pushd %~dp0
-
-REM Command file for Sphinx documentation
-
-if "%SPHINXBUILD%" == "" (
-	set SPHINXBUILD=sphinx-build
-)
-set SOURCEDIR=.
-set BUILDDIR=_build
-
-if "%1" == "" goto help
-
-%SPHINXBUILD% >NUL 2>NUL
-if errorlevel 9009 (
-	echo.
-	echo.The 'sphinx-build' command was not found. Make sure you have Sphinx
-	echo.installed, then set the SPHINXBUILD environment variable to point
-	echo.to the full path of the 'sphinx-build' executable. Alternatively you
-	echo.may add the Sphinx directory to PATH.
-	echo.
-	echo.If you don't have Sphinx installed, grab it from
-	echo.http://sphinx-doc.org/
-	exit /b 1
-)
-
-%SPHINXBUILD% -M %1 %SOURCEDIR% %BUILDDIR% %SPHINXOPTS%
-goto end
-
-:help
-%SPHINXBUILD% -M help %SOURCEDIR% %BUILDDIR% %SPHINXOPTS%
-
-:end
-popd
--- a/doc/source/pyModeS.c_common.rst
+++ b/doc/source/pyModeS.c_common.rst
@@ -0,0 +1,7 @@
+pyModeS.c\_common module
+========================
+
+.. automodule:: pyModeS.c_common
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.common.rst
+++ b/doc/source/pyModeS.common.rst
@@ -0,0 +1,7 @@
+pyModeS.common module
+=====================
+
+.. automodule:: pyModeS.common
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.acas.rst
+++ b/doc/source/pyModeS.decoder.acas.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.acas module
 ===========================

 .. automodule:: pyModeS.decoder.acas
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.adsb.rst
+++ b/doc/source/pyModeS.decoder.adsb.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.adsb module
 ===========================

 .. automodule:: pyModeS.decoder.adsb
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.allcall.rst
+++ b/doc/source/pyModeS.decoder.allcall.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.allcall module
 ==============================

 .. automodule:: pyModeS.decoder.allcall
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.bds.bds05.rst
+++ b/doc/source/pyModeS.decoder.bds.bds05.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.bds.bds05 module
 ================================

 .. automodule:: pyModeS.decoder.bds.bds05
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.bds.bds06.rst
+++ b/doc/source/pyModeS.decoder.bds.bds06.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.bds.bds06 module
 ================================

 .. automodule:: pyModeS.decoder.bds.bds06
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.bds.bds08.rst
+++ b/doc/source/pyModeS.decoder.bds.bds08.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.bds.bds08 module
 ================================

 .. automodule:: pyModeS.decoder.bds.bds08
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.bds.bds09.rst
+++ b/doc/source/pyModeS.decoder.bds.bds09.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.bds.bds09 module
 ================================

 .. automodule:: pyModeS.decoder.bds.bds09
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.bds.bds10.rst
+++ b/doc/source/pyModeS.decoder.bds.bds10.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.bds.bds10 module
 ================================

 .. automodule:: pyModeS.decoder.bds.bds10
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.bds.bds17.rst
+++ b/doc/source/pyModeS.decoder.bds.bds17.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.bds.bds17 module
 ================================

 .. automodule:: pyModeS.decoder.bds.bds17
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.bds.bds20.rst
+++ b/doc/source/pyModeS.decoder.bds.bds20.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.bds.bds20 module
 ================================

 .. automodule:: pyModeS.decoder.bds.bds20
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.bds.bds30.rst
+++ b/doc/source/pyModeS.decoder.bds.bds30.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.bds.bds30 module
 ================================

 .. automodule:: pyModeS.decoder.bds.bds30
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.bds.bds40.rst
+++ b/doc/source/pyModeS.decoder.bds.bds40.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.bds.bds40 module
 ================================

 .. automodule:: pyModeS.decoder.bds.bds40
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.bds.bds44.rst
+++ b/doc/source/pyModeS.decoder.bds.bds44.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.bds.bds44 module
 ================================

 .. automodule:: pyModeS.decoder.bds.bds44
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.bds.bds45.rst
+++ b/doc/source/pyModeS.decoder.bds.bds45.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.bds.bds45 module
 ================================

 .. automodule:: pyModeS.decoder.bds.bds45
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.bds.bds50.rst
+++ b/doc/source/pyModeS.decoder.bds.bds50.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.bds.bds50 module
 ================================

 .. automodule:: pyModeS.decoder.bds.bds50
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.bds.bds53.rst
+++ b/doc/source/pyModeS.decoder.bds.bds53.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.bds.bds53 module
 ================================

 .. automodule:: pyModeS.decoder.bds.bds53
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.bds.bds60.rst
+++ b/doc/source/pyModeS.decoder.bds.bds60.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.bds.bds60 module
 ================================

 .. automodule:: pyModeS.decoder.bds.bds60
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.bds.rst
+++ b/doc/source/pyModeS.decoder.bds.rst
@@ -2,14 +2,15 @@ pyModeS.decoder.bds package
 ===========================

 .. automodule:: pyModeS.decoder.bds
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:

 Submodules
 ----------

 .. toctree::
+   :maxdepth: 4

   pyModeS.decoder.bds.bds05
   pyModeS.decoder.bds.bds06
@@ -25,4 +26,3 @@ Submodules
   pyModeS.decoder.bds.bds50
   pyModeS.decoder.bds.bds53
   pyModeS.decoder.bds.bds60
-
--- a/doc/source/pyModeS.decoder.commb.rst
+++ b/doc/source/pyModeS.decoder.commb.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.commb module
 ============================

 .. automodule:: pyModeS.decoder.commb
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.common.rst
+++ b/doc/source/pyModeS.decoder.common.rst
@@ -1,7 +0,0 @@
-pyModeS.decoder.common module
-=============================
-
-.. automodule:: pyModeS.decoder.common
-    :members:
-    :undoc-members:
-    :show-inheritance:
--- a/doc/source/pyModeS.decoder.ehs.rst
+++ b/doc/source/pyModeS.decoder.ehs.rst
@@ -1,7 +0,0 @@
-pyModeS.decoder.ehs module
-==========================
-
-.. automodule:: pyModeS.decoder.ehs
-    :members:
-    :undoc-members:
-    :show-inheritance:
--- a/doc/source/pyModeS.decoder.els.rst
+++ b/doc/source/pyModeS.decoder.els.rst
@@ -1,7 +0,0 @@
-pyModeS.decoder.els module
-==========================
-
-.. automodule:: pyModeS.decoder.els
-    :members:
-    :undoc-members:
-    :show-inheritance:
--- a/doc/source/pyModeS.decoder.rst
+++ b/doc/source/pyModeS.decoder.rst
@@ -2,29 +2,28 @@ pyModeS.decoder package
 =======================

 .. automodule:: pyModeS.decoder
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:

 Subpackages
 -----------

 .. toctree::
+   :maxdepth: 4

-    pyModeS.decoder.bds
+   pyModeS.decoder.bds

 Submodules
 ----------

 .. toctree::
+   :maxdepth: 4

   pyModeS.decoder.acas
   pyModeS.decoder.adsb
   pyModeS.decoder.allcall
   pyModeS.decoder.commb
-   pyModeS.decoder.common
-   pyModeS.decoder.ehs
-   pyModeS.decoder.els
   pyModeS.decoder.surv
   pyModeS.decoder.uncertainty
-
+   pyModeS.decoder.uplink
--- a/doc/source/pyModeS.decoder.surv.rst
+++ b/doc/source/pyModeS.decoder.surv.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.surv module
 ===========================

 .. automodule:: pyModeS.decoder.surv
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.uncertainty.rst
+++ b/doc/source/pyModeS.decoder.uncertainty.rst
@@ -2,6 +2,6 @@ pyModeS.decoder.uncertainty module
 ==================================

 .. automodule:: pyModeS.decoder.uncertainty
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.decoder.uplink.rst
+++ b/doc/source/pyModeS.decoder.uplink.rst
@@ -0,0 +1,7 @@
+pyModeS.decoder.uplink module
+=============================
+
+.. automodule:: pyModeS.decoder.uplink
+   :members:
+   :undoc-members:
+   :show-inheritance:
--- a/doc/source/pyModeS.extra.aero.rst
+++ b/doc/source/pyModeS.extra.aero.rst
@@ -1,7 +0,0 @@
-pyModeS.extra.aero module
-=========================
-
-.. automodule:: pyModeS.extra.aero
-    :members:
-    :undoc-members:
-    :show-inheritance:
--- a/doc/source/pyModeS.extra.rst
+++ b/doc/source/pyModeS.extra.rst
@@ -1,16 +0,0 @@
-pyModeS.extra package
-=====================
-
-.. automodule:: pyModeS.extra
-    :members:
-    :undoc-members:
-    :show-inheritance:
-
-Submodules
----------
-
-.. toctree::
-
-   pyModeS.extra.aero
-   pyModeS.extra.tcpclient
-
--- a/doc/source/pyModeS.extra.tcpclient.rst
+++ b/doc/source/pyModeS.extra.tcpclient.rst
@@ -1,7 +0,0 @@
-pyModeS.extra.tcpclient module
-==============================
-
-.. automodule:: pyModeS.extra.tcpclient
-    :members:
-    :undoc-members:
-    :show-inheritance:
--- a/doc/source/pyModeS.rst
+++ b/doc/source/pyModeS.rst
@@ -2,16 +2,23 @@ pyModeS package
 ===============

 .. automodule:: pyModeS
-    :members:
-    :undoc-members:
-    :show-inheritance:
+   :members:
+   :undoc-members:
+   :show-inheritance:

 Subpackages
 -----------

 .. toctree::
+   :maxdepth: 4

-    pyModeS.decoder
-    pyModeS.extra
-    pyModeS.streamer
+   pyModeS.decoder

+Submodules
+----------
+
+.. toctree::
+   :maxdepth: 4
+
+   pyModeS.c_common
+   pyModeS.common
--- a/doc/source/pyModeS.streamer.rst
+++ b/doc/source/pyModeS.streamer.rst
@@ -1,16 +0,0 @@
-pyModeS.streamer package
-========================
-
-.. automodule:: pyModeS.streamer
-    :members:
-    :undoc-members:
-    :show-inheritance:
-
-Submodules
----------
-
-.. toctree::
-
-   pyModeS.streamer.screen
-   pyModeS.streamer.stream
-
--- a/doc/source/pyModeS.streamer.screen.rst
+++ b/doc/source/pyModeS.streamer.screen.rst
@@ -1,7 +0,0 @@
-pyModeS.streamer.screen module
-==============================
-
-.. automodule:: pyModeS.streamer.screen
-    :members:
-    :undoc-members:
-    :show-inheritance:
--- a/doc/source/pyModeS.streamer.stream.rst
+++ b/doc/source/pyModeS.streamer.stream.rst
@@ -1,7 +0,0 @@
-pyModeS.streamer.stream module
-==============================
-
-.. automodule:: pyModeS.streamer.stream
-    :members:
-    :undoc-members:
-    :show-inheritance:
--- a/doc/warnings
+++ b/doc/warnings
--- a/pyModeS/init.py
+++ b/pyModeS/init.py
@@ -1,17 +1,21 @@
-from __future__ import absolute_import, print_function, division
-
 import os
 import warnings

-from .decoder.common import *
+try:
+    from . import c_common as common
+    from .c_common import *
+except:
+    from . import common
+    from .common import *
+
 from .decoder import tell
 from .decoder import adsb
 from .decoder import commb
-from .decoder import common
 from .decoder import bds
 from .extra import aero
 from .extra import tcpclient

+
 warnings.simplefilter("once", DeprecationWarning)

 dirpath = os.path.dirname(os.path.realpath(__file__))
--- a/pyModeS/c_common.pxd
+++ b/pyModeS/c_common.pxd
@@ -0,0 +1,23 @@
+# cython: language_level=3
+
+cdef int char_to_int(unsigned char binstr)
+cdef unsigned char int_to_char(unsigned char i)
+
+cpdef str hex2bin(str hexstr)
+cpdef long bin2int(str binstr)
+cpdef long hex2int(str binstr)
+
+cpdef unsigned char df(str msg)
+cpdef long crc(str msg, bint encode=*)
+
+cpdef long floor(double x)
+cpdef str icao(str msg)
+cpdef bint is_icao_assigned(str icao)
+
+cpdef int typecode(str msg)
+cpdef int cprNL(double lat)
+cpdef str idcode(str msg)
+cpdef int altcode(str msg)
+
+cpdef str data(str msg)
+cpdef bint allzeros(str msg)
--- a/pyModeS/c_common.pyx
+++ b/pyModeS/c_common.pyx
@@ -0,0 +1,429 @@
+# cython: language_level=3
+
+cimport cython
+from cpython cimport array
+from cpython.bytes cimport PyBytes_GET_SIZE
+from cpython.bytearray cimport PyByteArray_GET_SIZE
+
+from libc.math cimport abs, cos, acos, fabs, M_PI as pi, floor as c_floor
+
+
+cdef int char_to_int(unsigned char binstr):
+    if 48 <= binstr <= 57:  # 0 to 9
+        return binstr - 48
+    if 97 <= binstr <= 102: # a to f
+        return binstr - 97 + 10
+    if 65 <= binstr <= 70: # A to F
+        return binstr - 65 + 10
+    return 0
+
+cdef unsigned char int_to_char(unsigned char i):
+    if i < 10:
+        return 48 + i  # "0" + i
+    return 97 - 10 + i  # "a" - 10 + i
+
+@cython.boundscheck(False)
+@cython.overflowcheck(False)
+cpdef str hex2bin(str hexstr):
+    """Convert a hexdecimal string to binary string, with zero fillings."""
+    # num_of_bits = len(hexstr) * 4
+    cdef hexbytes = bytes(hexstr.encode())
+    cdef Py_ssize_t len_hexstr = PyBytes_GET_SIZE(hexbytes)
+    # binstr = bin(int(hexbytes, 16))[2:].zfill(int(num_of_bits))
+    cdef bytearray _binstr = bytearray(4 * len_hexstr)
+    cdef unsigned char[:] binstr = _binstr
+    cdef unsigned char int_
+    cdef Py_ssize_t i
+    for i in range(len_hexstr):
+        int_ = char_to_int(hexbytes[i])
+        binstr[4*i] = int_to_char((int_  >> 3) & 1)
+        binstr[4*i+1] = int_to_char((int_ >> 2) & 1)
+        binstr[4*i+2] = int_to_char((int_ >> 1) & 1)
+        binstr[4*i+3] = int_to_char((int_) & 1)
+    return _binstr.decode()
+
+@cython.boundscheck(False)
+cpdef long bin2int(str binstr):
+    """Convert a binary string to integer."""
+    # return int(binstr, 2)
+    cdef bytearray binbytes = bytearray(binstr.encode())
+    cdef Py_ssize_t len_ = PyByteArray_GET_SIZE(binbytes)
+    cdef long cumul = 0
+    cdef unsigned char[:] v_binstr = binbytes
+    for i in range(len_):
+        cumul = 2*cumul + char_to_int(v_binstr[i])
+    return cumul
+
+@cython.boundscheck(False)
+cpdef long hex2int(str hexstr):
+    """Convert a binary string to integer."""
+    # return int(hexstr, 2)
+    cdef bytearray binbytes = bytearray(hexstr.encode())
+    cdef Py_ssize_t len_ = PyByteArray_GET_SIZE(binbytes)
+    cdef long cumul = 0
+    cdef unsigned char[:] v_hexstr = binbytes
+    for i in range(len_):
+        cumul = 16*cumul + char_to_int(v_hexstr[i])
+    return cumul
+
+@cython.boundscheck(False)
+cpdef unsigned char df(str msg):
+    """Decode Downlink Format vaule, bits 1 to 5."""
+    cdef str dfbin = hex2bin(msg[:2])
+    # return min(bin2int(dfbin[0:5]), 24)
+    cdef long df = bin2int(dfbin[0:5])
+    if df > 24:
+        return 24
+    return df
+
+# the CRC generator
+# G = [int("11111111", 2), int("11111010", 2), int("00000100", 2), int("10000000", 2)]
+cdef array.array _G = array.array('l', [0b11111111, 0b11111010, 0b00000100, 0b10000000])
+
+@cython.boundscheck(False)
+@cython.wraparound(False)
+cpdef long crc(str msg, bint encode=False):
+    """Mode-S Cyclic Redundancy Check.
+
+    Detect if bit error occurs in the Mode-S message. When encode option is on,
+    the checksum is generated.
+
+    Args:
+        msg (string): 28 bytes hexadecimal message string
+        encode (bool): True to encode the date only and return the checksum
+    Returns:
+        int: message checksum, or partity bits (encoder)
+
+    """
+    # the CRC generator
+    # G = [int("11111111", 2), int("11111010", 2), int("00000100", 2), int("10000000", 2)]
+    # cdef array.array _G = array.array('l', [0b11111111, 0b11111010, 0b00000100, 0b10000000])
+    cdef long[4] G = _G
+
+    # msgbin_split = wrap(msgbin, 8)
+    # mbytes = list(map(bin2int, msgbin_split))
+    cdef bytearray _msgbin = bytearray(hex2bin(msg).encode())
+    cdef unsigned char[:] msgbin = _msgbin
+
+    cdef Py_ssize_t len_msgbin = PyByteArray_GET_SIZE(_msgbin)
+    cdef Py_ssize_t len_mbytes = len_msgbin // 8
+    cdef Py_ssize_t i
+
+    if encode:
+        for i in range(len_msgbin - 24, len_msgbin):
+            msgbin[i] = 0
+
+    cdef array.array _mbytes = array.array(
+        'l', [bin2int(_msgbin[8*i:8*i+8].decode()) for i in range(len_mbytes)]
+    )
+
+    cdef long[:] mbytes = _mbytes
+
+    cdef long bits, mask
+    cdef Py_ssize_t ibyte, ibit
+
+    for ibyte in range(len_mbytes - 3):
+        for ibit in range(8):
+            mask = 0x80 >> ibit
+            bits = mbytes[ibyte] & mask
+
+            if bits > 0:
+                mbytes[ibyte] = mbytes[ibyte] ^ (G[0] >> ibit)
+                mbytes[ibyte + 1] = mbytes[ibyte + 1] ^ (
+                    0xFF & ((G[0] << 8 - ibit) | (G[1] >> ibit))
+                )
+                mbytes[ibyte + 2] = mbytes[ibyte + 2] ^ (
+                    0xFF & ((G[1] << 8 - ibit) | (G[2] >> ibit))
+                )
+                mbytes[ibyte + 3] = mbytes[ibyte + 3] ^ (
+                    0xFF & ((G[2] << 8 - ibit) | (G[3] >> ibit))
+                )
+
+    cdef long result = (mbytes[len_mbytes-3] << 16) | (mbytes[len_mbytes-2] << 8) | mbytes[len_mbytes-1]
+
+    return result
+
+
+
+cpdef long floor(double x):
+    """Mode-S floor function.
+
+    Defined as the greatest integer value k, such that k <= x
+    For example: floor(3.6) = 3 and floor(-3.6) = -4
+
+    """
+    return <long> c_floor(x)
+
+cpdef str icao(str msg):
+    """Calculate the ICAO address from an Mode-S message.
+
+    Applicable only with DF4, DF5, DF20, DF21 messages.
+
+    Args:
+        msg (String): 28 bytes hexadecimal message string
+
+    Returns:
+        String: ICAO address in 6 bytes hexadecimal string
+
+    """
+    cdef unsigned char DF = df(msg)
+    cdef long c0, c1
+
+    if DF in (11, 17, 18):
+        addr = msg[2:8]
+    elif DF in (0, 4, 5, 16, 20, 21):
+        c0 = crc(msg, encode=True)
+        c1 = hex2int(msg[-6:])
+        addr = "%06X" % (c0 ^ c1)
+    else:
+        addr = None
+
+    return addr
+
+
+cpdef bint is_icao_assigned(str icao):
+    """Check whether the ICAO address is assigned (Annex 10, Vol 3)."""
+    if (icao is None) or (not isinstance(icao, str)) or (len(icao) != 6):
+        return False
+
+    cdef long icaoint = hex2int(icao)
+
+    if 0x200000 < icaoint < 0x27FFFF:
+        return False  # AFI
+    if 0x280000 < icaoint < 0x28FFFF:
+        return False  # SAM
+    if 0x500000 < icaoint < 0x5FFFFF:
+        return False  # EUR, NAT
+    if 0x600000 < icaoint < 0x67FFFF:
+        return False  # MID
+    if 0x680000 < icaoint < 0x6F0000:
+        return False  # ASIA
+    if 0x900000 < icaoint < 0x9FFFFF:
+        return False  # NAM, PAC
+    if 0xB00000 < icaoint < 0xBFFFFF:
+        return False  # CAR
+    if 0xD00000 < icaoint < 0xDFFFFF:
+        return False  # future
+    if 0xF00000 < icaoint < 0xFFFFFF:
+        return False  # future
+
+    return True
+
+@cython.boundscheck(False)
+@cython.wraparound(False)
+cpdef int typecode(str msg):
+    """Type code of ADS-B message
+
+    Args:
+        msg (string): 28 bytes hexadecimal message string
+
+    Returns:
+        int: type code number
+    """
+    if df(msg) not in (17, 18):
+        return -1
+        # return None
+
+    cdef str tcbin = hex2bin(msg[8:10])
+    return bin2int(tcbin[0:5])
+
+@cython.cdivision(True)
+cpdef int cprNL(double lat):
+    """NL() function in CPR decoding."""
+
+    if abs(lat) <= 1e-08:
+        return 59
+    elif abs(abs(lat) - 87) <= 1e-08 + 1e-05 * 87:
+        return 2
+    elif lat > 87 or lat < -87:
+        return 1
+
+    cdef int nz = 15
+    cdef double a = 1 - cos(pi / (2 * nz))
+    cdef double b = cos(pi / 180.0 * fabs(lat)) ** 2
+    cdef double nl = 2 * pi / (acos(1 - a / b))
+    NL = floor(nl)
+    return NL
+
+@cython.boundscheck(False)
+@cython.wraparound(False)
+cpdef str idcode(str msg):
+    """Compute identity (squawk code).
+
+    Applicable only for DF5 or DF21 messages, bit 20-32.
+    credit: @fbyrkjeland
+
+    Args:
+        msg (String): 28 bytes hexadecimal message string
+
+    Returns:
+        string: squawk code
+
+    """
+    if df(msg) not in [5, 21]:
+        raise RuntimeError("Message must be Downlink Format 5 or 21.")
+
+    cdef bytearray _mbin = bytearray(hex2bin(msg).encode())
+    cdef unsigned char[:] mbin = _mbin
+
+    cdef bytearray _idcode = bytearray(4)
+    cdef unsigned char[:] idcode = _idcode
+
+    cdef unsigned char C1 = mbin[19]
+    cdef unsigned char A1 = mbin[20]
+    cdef unsigned char C2 = mbin[21]
+    cdef unsigned char A2 = mbin[22]
+    cdef unsigned char C4 = mbin[23]
+    cdef unsigned char A4 = mbin[24]
+    # _ = mbin[25]
+    cdef unsigned char B1 = mbin[26]
+    cdef unsigned char D1 = mbin[27]
+    cdef unsigned char B2 = mbin[28]
+    cdef unsigned char D2 = mbin[29]
+    cdef unsigned char B4 = mbin[30]
+    cdef unsigned char D4 = mbin[31]
+
+    # byte1 = int(A4 + A2 + A1, 2)
+    # byte2 = int(B4 + B2 + B1, 2)
+    # byte3 = int(C4 + C2 + C1, 2)
+    # byte4 = int(D4 + D2 + D1, 2)
+
+    idcode[0] = int_to_char((char_to_int(A4)*2 + char_to_int(A2))*2 + char_to_int(A1))
+    idcode[1] = int_to_char((char_to_int(B4)*2 + char_to_int(B2))*2 + char_to_int(B1))
+    idcode[2] = int_to_char((char_to_int(C4)*2 + char_to_int(C2))*2 + char_to_int(C1))
+    idcode[3] = int_to_char((char_to_int(D4)*2 + char_to_int(D2))*2 + char_to_int(D1))
+
+    return _idcode.decode()
+
+    #return str(byte1) + str(byte2) + str(byte3) + str(byte4)
+
+
+@cython.boundscheck(False)
+@cython.wraparound(False)
+cpdef int altcode(str msg):
+    """Compute the altitude.
+
+    Applicable only for DF4 or DF20 message, bit 20-32.
+    credit: @fbyrkjeland
+
+    Args:
+        msg (String): 28 bytes hexadecimal message string
+
+    Returns:
+        int: altitude in ft
+
+    """
+    if df(msg) not in [0, 4, 16, 20]:
+        raise RuntimeError("Message must be Downlink Format 0, 4, 16, or 20.")
+
+    # Altitude code, bit 20-32
+    cdef bytearray _mbin = bytearray(hex2bin(msg).encode())
+    cdef unsigned char[:] mbin = _mbin
+
+    cdef char mbit = mbin[25]  # M bit: 26
+    cdef char qbit = mbin[27]  # Q bit: 28
+    cdef int alt = 0
+    cdef bytearray vbin
+    cdef bytearray _graybytes = bytearray(11)
+    cdef unsigned char[:] graybytes = _graybytes
+
+    if mbit == 48:  # unit in ft, "0" -> 48
+        if qbit == 49:  # 25ft interval, "1" -> 49
+            vbin = _mbin[19:25] + _mbin[26:27] + _mbin[28:32]
+            alt = bin2int(vbin.decode()) * 25 - 1000
+        if qbit == 48:  # 100ft interval, above 50175ft, "0" -> 48
+            graybytes[8] = mbin[19]
+            graybytes[2] = mbin[20]
+            graybytes[9] = mbin[21]
+            graybytes[3] = mbin[22]
+            graybytes[10] = mbin[23]
+            graybytes[4] = mbin[24]
+            # _ = mbin[25]
+            graybytes[5] = mbin[26]
+            # cdef char D1 = mbin[27]  # always zero
+            graybytes[6] = mbin[28]
+            graybytes[0] = mbin[29]
+            graybytes[7] = mbin[30]
+            graybytes[1] = mbin[31]
+            # graybytes = D2 + D4 + A1 + A2 + A4 + B1 + B2 + B4 + C1 + C2 + C4
+
+            alt = gray2alt(_graybytes.decode())
+
+    if mbit == 49:  # unit in meter, "1" -> 49
+        vbin = _mbin[19:25] + _mbin[26:31]
+        alt = int(bin2int(vbin.decode()) * 3.28084)  # convert to ft
+
+    return alt
+
+
+
+cpdef int gray2alt(str codestr):
+    cdef str gc500 = codestr[:8]
+    cdef int n500 = gray2int(gc500)
+
+    # in 100-ft step must be converted first
+    cdef str gc100 = codestr[8:]
+    cdef int n100 = gray2int(gc100)
+
+    if n100 in [0, 5, 6]:
+        return -1
+        #return None
+
+    if n100 == 7:
+        n100 = 5
+
+    if n500 % 2:
+        n100 = 6 - n100
+
+    alt = (n500 * 500 + n100 * 100) - 1300
+    return alt
+
+
+cdef int gray2int(str graystr):
+    """Convert greycode to binary."""
+    cdef int num = bin2int(graystr)
+    num ^= num >> 8
+    num ^= num >> 4
+    num ^= num >> 2
+    num ^= num >> 1
+    return num
+
+
+cpdef str data(str msg):
+    """Return the data frame in the message, bytes 9 to 22."""
+    return msg[8:-6]
+
+
+cpdef bint allzeros(str msg):
+    """Check if the data bits are all zeros.
+
+    Args:
+        msg (String): 28 bytes hexadecimal message string
+
+    Returns:
+        bool: True or False
+
+    """
+    d = hex2bin(data(msg))
+
+    if bin2int(d) > 0:
+        return False
+    else:
+        return True
+
+
+def wrongstatus(data, sb, msb, lsb):
+    """Check if the status bit and field bits are consistency.
+
+    This Function is used for checking BDS code versions.
+
+    """
+    # status bit, most significant bit, least significant bit
+    status = int(data[sb - 1])
+    value = bin2int(data[msb - 1 : lsb])
+
+    if not status:
+        if value != 0:
+            return True
+
+    return False
--- a/pyModeS/decoder/common.py
+++ b/pyModeS/decoder/common.py
@@ -1,4 +1,3 @@
-from __future__ import absolute_import, print_function, division
 import numpy as np
 from textwrap import wrap

@@ -15,36 +14,15 @@ def hex2int(hexstr):
    return int(hexstr, 16)


-def int2hex(n):
-    """Convert a integer to hexadecimal string."""
-    # strip 'L' for python 2
-    return hex(n)[2:].rjust(6, "0").upper().rstrip("L")
-
-
 def bin2int(binstr):
    """Convert a binary string to integer."""
    return int(binstr, 2)


-def bin2hex(hexstr):
-    """Convert a hexdecimal string to integer."""
-    return int2hex(bin2int(hexstr))
-
-
-def bin2np(binstr):
-    """Convert a binary string to numpy array."""
-    return np.array([int(i) for i in binstr])
-
-
-def np2bin(npbin):
-    """Convert a binary numpy array to string."""
-    return np.array2string(npbin, separator="")[1:-1]
-
-
 def df(msg):
-    """Decode Downlink Format vaule, bits 1 to 5."""
-    msgbin = hex2bin(msg)
-    return min(bin2int(msgbin[0:5]), 24)
+    """Decode Downlink Format value, bits 1 to 5."""
+    dfbin = hex2bin(msg[:2])
+    return min(bin2int(dfbin[0:5]), 24)


 def crc(msg, encode=False):
@@ -100,7 +78,7 @@ def crc_legacy(msg, encode=False):
    )
    ng = len(generator)

-    msgnpbin = bin2np(hex2bin(msg))
+    msgnpbin = np.array([int(i) for i in hex2bin(msg)])

    if encode:
        msgnpbin[-24:] = [0] * 24
@@ -114,7 +92,9 @@ def crc_legacy(msg, encode=False):
        msgnpbin[i : i + ng] = np.bitwise_xor(msgnpbin[i : i + ng], generator)

    # last 24 bits
-    reminder = bin2int(np2bin(msgnpbin[-24:]))
+    msgbin = np.array2string(msgnpbin[-24:], separator="")[1:-1]
+    reminder = bin2int(msgbin)
+
    return reminder


@@ -146,7 +126,7 @@ def icao(msg):
        addr = msg[2:8]
    elif DF in (0, 4, 5, 16, 20, 21):
        c0 = crc(msg, encode=True)
-        c1 = hex2int(msg[-6:])
+        c1 = int(msg[-6:], 16)
        addr = "%06X" % (c0 ^ c1)
    else:
        addr = None
@@ -159,7 +139,7 @@ def is_icao_assigned(icao):
    if (icao is None) or (not isinstance(icao, str)) or (len(icao) != 6):
        return False

-    icaoint = hex2int(icao)
+    icaoint = int(icao, 16)

    if 0x200000 < icaoint < 0x27FFFF:
        return False  # AFI
@@ -195,20 +175,18 @@ def typecode(msg):
    if df(msg) not in (17, 18):
        return None

-    msgbin = hex2bin(msg)
-    return bin2int(msgbin[32:37])
+    tcbin = hex2bin(msg[8:10])
+    return bin2int(tcbin[0:5])


 def cprNL(lat):
    """NL() function in CPR decoding."""

-    if lat == 0:
+    if np.isclose(lat, 0):
        return 59
-
-    if lat == 87 or lat == -87:
+    elif np.isclose(abs(lat), 87):
        return 2
-
-    if lat > 87 or lat < -87:
+    elif lat > 87 or lat < -87:
        return 1

    nz = 15
--- a/pyModeS/decoder/init.py
+++ b/pyModeS/decoder/init.py
@@ -1,9 +1,6 @@
-from __future__ import absolute_import, print_function, division
-
-from pyModeS.decoder import adsb, commb, common, bds
-
-
 def tell(msg):
+    from pyModeS import common, adsb, commb, bds
+
    def _print(label, value, unit=None):
        print("%20s: " % label, end="")
        print("%s " % value, end="")
@@ -20,7 +17,7 @@ def tell(msg):
    _print("Downlink Format", df)

    if df == 17:
-        _print("Protocal", "Mode-S Extended Squitter (ADS-B)")
+        _print("Protocol", "Mode-S Extended Squitter (ADS-B)")

        tc = common.typecode(msg)
        if 1 <= tc <= 4:  # callsign
@@ -29,7 +26,7 @@ def tell(msg):
            _print("Callsign:", callsign)

        if 5 <= tc <= 8:  # surface position
-            _print("Type", "Surface postition")
+            _print("Type", "Surface position")
            oe = adsb.oe_flag(msg)
            msgbin = common.hex2bin(msg)
            cprlat = common.bin2int(msgbin[54:71]) / 131072.0
@@ -75,11 +72,11 @@ def tell(msg):
            _print("Altitude", alt, "feet")

    if df == 20:
-        _print("Protocal", "Mode-S Comm-B altitude reply")
+        _print("Protocol", "Mode-S Comm-B altitude reply")
        _print("Altitude", common.altcode(msg), "feet")

    if df == 21:
-        _print("Protocal", "Mode-S Comm-B identity reply")
+        _print("Protocol", "Mode-S Comm-B identity reply")
        _print("Squawk code", common.idcode(msg))

    if df == 20 or df == 21:
--- a/pyModeS/decoder/acas.py
+++ b/pyModeS/decoder/acas.py
@@ -1,23 +1,5 @@
-# Copyright (C) 2018 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
 """
 Decoding Air-Air Surveillance (ACAS) DF=0/16

 [To be implemented]
 """
-
-from __future__ import absolute_import, print_function, division
-from pyModeS.decoder import common
--- a/pyModeS/decoder/adsb.py
+++ b/pyModeS/decoder/adsb.py
@@ -1,44 +1,25 @@
-# Copyright (C) 2015 Junzi Sun (TU Delft)
+"""ADS-B module.

-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
+The ADS-B module also imports functions from the following modules:

-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-"""ADS-B Wrapper.
-
-The ADS-B wrapper also imports functions from the following modules:
-
- pyModeS.decoder.bds.bds05
-    Functions: ``airborne_position``, ``airborne_position_with_ref``, ``altitude``
- pyModeS.decoder.bds.bds06
-    Functions: ``surface_position``, ``surface_position_with_ref``, ``surface_velocity``
- pyModeS.decoder.bds.bds08
-    Functions: ``category``, ``callsign``
- pyModeS.decoder.bds.bds09
-    Functions: ``airborne_velocity``, ``altitude_diff``
+- pyModeS.decoder.bds.bds05: ``airborne_position()``, ``airborne_position_with_ref()``, ``altitude()``
+- pyModeS.decoder.bds.bds06: ``surface_position()``, ``surface_position_with_ref()``, ``surface_velocity()``
+- pyModeS.decoder.bds.bds08: ``category()``, ``callsign()``
+- pyModeS.decoder.bds.bds09: ``airborne_velocity()``, ``altitude_diff()``

 """

-from __future__ import absolute_import, print_function, division
-
 import pyModeS as pms
-from pyModeS.decoder import common
+
+from pyModeS import common
+
 from pyModeS.decoder import uncertainty

 # from pyModeS.decoder.bds import bds05, bds06, bds09
 from pyModeS.decoder.bds.bds05 import (
    airborne_position,
    airborne_position_with_ref,
-    altitude,
+    altitude as altitude05,
 )
 from pyModeS.decoder.bds.bds06 import (
    surface_position,
@@ -62,27 +43,32 @@ def typecode(msg):


 def position(msg0, msg1, t0, t1, lat_ref=None, lon_ref=None):
-    """Decode position from a pair of even and odd position message
-    (works with both airborne and surface position messages)
+    """Decode surface or airborne position from a pair of even and odd
+    position messages.
+
+    Note, that to decode surface position using the position message pair,
+    the reference position has to be provided.

    Args:
-        msg0 (string): even message (28 bytes hexadecimal string)
-        msg1 (string): odd message (28 bytes hexadecimal string)
+        msg0 (string): even message (28 hexdigits)
+        msg1 (string): odd message (28 hexdigits)
        t0 (int): timestamps for the even message
        t1 (int): timestamps for the odd message
+        lat_ref (float): latitude of reference position
+        lon_ref (float): longitude of reference position

    Returns:
        (float, float): (latitude, longitude) of the aircraft
+
    """
    tc0 = typecode(msg0)
    tc1 = typecode(msg1)

    if 5 <= tc0 <= 8 and 5 <= tc1 <= 8:
-        if (not lat_ref) or (not lon_ref):
+        if lat_ref is None or lon_ref is None:
            raise RuntimeError(
-                "Surface position encountered, a reference \
-                               position lat/lon required. Location of \
-                               receiver can be used."
+                "Surface position encountered, a reference position"
+                " lat/lon required. Location of receiver can be used."
            )
        else:
            return surface_position(msg0, msg1, t0, t1, lat_ref, lon_ref)
@@ -96,19 +82,20 @@ def position(msg0, msg1, t0, t1, lat_ref=None, lon_ref=None):
        return airborne_position(msg0, msg1, t0, t1)

    else:
-        raise RuntimeError("incorrect or inconsistant message types")
+        raise RuntimeError("Incorrect or inconsistent message types")


 def position_with_ref(msg, lat_ref, lon_ref):
-    """Decode position with only one message,
-    knowing reference nearby location, such as previously
-    calculated location, ground station, or airport location, etc.
-    Works with both airborne and surface position messages.
+    """Decode position with only one message.
+
+    A reference position is required, which can be previously
+    calculated location, ground station, or airport location.
+    The function works with both airborne and surface position messages.
    The reference position shall be with in 180NM (airborne) or 45NM (surface)
    of the true position.

    Args:
-        msg (string): even message (28 bytes hexadecimal string)
+        msg (str): even message (28 hexdigits)
        lat_ref: previous known latitude
        lon_ref: previous known longitude

@@ -125,72 +112,62 @@ def position_with_ref(msg, lat_ref, lon_ref):
        return airborne_position_with_ref(msg, lat_ref, lon_ref)

    else:
-        raise RuntimeError("incorrect or inconsistant message types")
+        raise RuntimeError("incorrect or inconsistent message types")


 def altitude(msg):
-    """Decode aircraft altitude
+    """Decode aircraft altitude.

    Args:
-        msg (string): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        int: altitude in feet
-    """

+    """
    tc = typecode(msg)

    if tc < 5 or tc == 19 or tc > 22:
        raise RuntimeError("%s: Not a position message" % msg)

-    if tc >= 5 and tc <= 8:
+    elif tc >= 5 and tc <= 8:
        # surface position, altitude 0
        return 0

-    msgbin = common.hex2bin(msg)
-    q = msgbin[47]
-    if q:
-        n = common.bin2int(msgbin[40:47] + msgbin[48:52])
-        alt = n * 25 - 1000
-        return alt
    else:
-        return None
+        # airborn position
+        return altitude05(msg)


-def velocity(msg, rtn_sources=False):
-    """Calculate the speed, heading, and vertical rate
-    (handles both airborne or surface message)
+def velocity(msg, source=False):
+    """Calculate the speed, heading, and vertical rate (handles both airborne or surface message).

    Args:
-        msg (string): 28 bytes hexadecimal message string
-        rtn_source (boolean): If the function will return
-            the sources for direction of travel and vertical
-            rate. This will change the return value from a four
-            element array to a six element array.
+        msg (str): 28 hexdigits string
+        source (boolean): Include direction and vertical rate sources in return. Default to False.
+            If set to True, the function will return six value instead of four.

    Returns:
-        (int, float, int, string, string, string): speed (kt),
-            ground track or heading (degree),
-            rate of climb/descent (ft/min), speed type
-            ('GS' for ground speed, 'AS' for airspeed),
-            direction source ('true_north' for ground track / true north
-            as refrence, 'mag_north' for magnetic north as reference),
-            rate of climb/descent source ('Baro' for barometer, 'GNSS'
-            for GNSS constellation).
-            
-            In the case of surface messages, None will be put in place
-            for vertical rate and its respective sources.
-    """
+        int, float, int, string, [string], [string]: Four or six parameters, including:
+            - Speed (kt)
+            - Angle (degree), either ground track or heading
+            - Vertical rate (ft/min)
+            - Speed type ('GS' for ground speed, 'AS' for airspeed)
+            - [Optional] Direction source ('TRUE_NORTH' or 'MAGENTIC_NORTH')
+            - [Optional] Vertical rate source ('BARO' or 'GNSS')

+        For surface messages, vertical rate and its respective sources are set to None.
+
+    """
    if 5 <= typecode(msg) <= 8:
-        return surface_velocity(msg, rtn_sources)
+        return surface_velocity(msg, source)

    elif typecode(msg) == 19:
-        return airborne_velocity(msg, rtn_sources)
+        return airborne_velocity(msg, source)

    else:
        raise RuntimeError(
-            "incorrect or inconsistant message types, expecting 4<TC<9 or TC=19"
+            "incorrect or inconsistent message types, expecting 4<TC<9 or TC=19"
        )


@@ -199,7 +176,7 @@ def speed_heading(msg):
    (handles both airborne or surface message)

    Args:
-        msg (string): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        (int, float): speed (kt), ground track or heading (degree)
@@ -211,7 +188,7 @@ def speed_heading(msg):
 def oe_flag(msg):
    """Check the odd/even flag. Bit 54, 0 for even, 1 for odd.
    Args:
-        msg (string): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string
    Returns:
        int: 0 or 1, for even or odd frame
    """
@@ -223,7 +200,7 @@ def version(msg):
    """ADS-B Version

    Args:
-        msg (string): 28 bytes hexadecimal message string, TC = 31
+        msg (str): 28 hexdigits string, TC = 31

    Returns:
        int: version number
@@ -245,7 +222,7 @@ def nuc_p(msg):
    """Calculate NUCp, Navigation Uncertainty Category - Position (ADS-B version 1)

    Args:
-        msg (string): 28 bytes hexadecimal message string,
+        msg (str): 28 hexdigits string,

    Returns:
        int: Horizontal Protection Limit
@@ -281,7 +258,7 @@ def nuc_v(msg):
    """Calculate NUCv, Navigation Uncertainty Category - Velocity (ADS-B version 1)

    Args:
-        msg (string): 28 bytes hexadecimal message string,
+        msg (str): 28 hexdigits string,

    Returns:
        int or string: 95% Horizontal Velocity Error
@@ -310,7 +287,7 @@ def nic_v1(msg, NICs):
    """Calculate NIC, navigation integrity category, for ADS-B version 1

    Args:
-        msg (string): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string
        NICs (int or string): NIC supplement

    Returns:
@@ -344,7 +321,7 @@ def nic_v2(msg, NICa, NICbc):
    """Calculate NIC, navigation integrity category, for ADS-B version 2

    Args:
-        msg (string): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string
        NICa (int or string): NIC supplement - A
        NICbc (int or srting): NIC supplement - B or C

@@ -382,7 +359,7 @@ def nic_s(msg):
    """Obtain NIC supplement bit, TC=31 message

    Args:
-        msg (string): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        int: NICs number (0 or 1)
@@ -404,7 +381,7 @@ def nic_a_c(msg):
    """Obtain NICa/c, navigation integrity category supplements a and c

    Args:
-        msg (string): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        (int, int): NICa and NICc number (0 or 1)
@@ -427,7 +404,7 @@ def nic_b(msg):
    """Obtain NICb, navigation integrity category supplement-b

    Args:
-        msg (string): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        int: NICb number (0 or 1)
@@ -449,7 +426,7 @@ def nac_p(msg):
    """Calculate NACp, Navigation Accuracy Category - Position

    Args:
-        msg (string): 28 bytes hexadecimal message string, TC = 29 or 31
+        msg (str): 28 hexdigits string, TC = 29 or 31

    Returns:
        int or string: 95% horizontal accuracy bounds, Estimated Position Uncertainty
@@ -484,7 +461,7 @@ def nac_v(msg):
    """Calculate NACv, Navigation Accuracy Category - Velocity

    Args:
-        msg (string): 28 bytes hexadecimal message string, TC = 19
+        msg (str): 28 hexdigits string, TC = 19

    Returns:
        int or string: 95% horizontal accuracy bounds for velocity, Horizontal Figure of Merit
@@ -513,7 +490,7 @@ def sil(msg, version):
    """Calculate SIL, Surveillance Integrity Level

    Args:
-        msg (string): 28 bytes hexadecimal message string with TC = 29, 31
+        msg (str): 28 hexdigits string with TC = 29, 31

    Returns:
        int or string: Probability of exceeding Horizontal Radius of Containment RCu
@@ -524,7 +501,7 @@ def sil(msg, version):

    if tc not in [29, 31]:
        raise RuntimeError(
-            "%s: Not a target state and status messag, \
+            "%s: Not a target state and status message, \
                           or operation status message, expecting TC = 29 or 31"
            % msg
        )
--- a/pyModeS/decoder/allcall.py
+++ b/pyModeS/decoder/allcall.py
@@ -1,23 +1,5 @@
-# Copyright (C) 2018 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
 """
 Decoding all call replies DF=11

 [To be implemented]
 """
-
-from __future__ import absolute_import, print_function, division
-from pyModeS.decoder import common
--- a/pyModeS/decoder/bds/init.py
+++ b/pyModeS/decoder/bds/init.py
@@ -18,11 +18,11 @@
 Common functions for Mode-S decoding
 """

-from __future__ import absolute_import, print_function, division
 import numpy as np

 from pyModeS.extra import aero
-from pyModeS.decoder import common
+from pyModeS import common
+
 from pyModeS.decoder.bds import (
    bds05,
    bds06,
@@ -45,7 +45,7 @@ def is50or60(msg, spd_ref, trk_ref, alt_ref):
    """Use reference ground speed and trk to determine BDS50 and DBS60.

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string
        spd_ref (float): reference speed (ADS-B ground speed), kts
        trk_ref (float): reference track (ADS-B track angle), deg
        alt_ref (float): reference altitude (ADS-B altitude), ft
@@ -108,7 +108,7 @@ def infer(msg, mrar=False):
    """Estimate the most likely BDS code of an message.

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string
        mrar (bool): Also infer MRAR (BDS 44) and MHR (BDS 45). Defaults to False.

    Returns:
@@ -125,7 +125,7 @@ def infer(msg, mrar=False):
        tc = common.typecode(msg)

        if 1 <= tc <= 4:
-            return "BDS08"  # indentification and category
+            return "BDS08"  # identification and category
        if 5 <= tc <= 8:
            return "BDS06"  # surface movement
        if 9 <= tc <= 18:
--- a/pyModeS/decoder/bds/bds05.py
+++ b/pyModeS/decoder/bds/bds05.py
@@ -1,36 +1,18 @@
-# Copyright (C) 2018 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-
 # ------------------------------------------
 #   BDS 0,5
 #   ADS-B TC=9-18
 #   Airborn position
 # ------------------------------------------

-
-from __future__ import absolute_import, print_function, division
-from pyModeS.decoder import common
+from pyModeS import common


 def airborne_position(msg0, msg1, t0, t1):
    """Decode airborn position from a pair of even and odd position message

    Args:
-        msg0 (string): even message (28 bytes hexadecimal string)
-        msg1 (string): odd message (28 bytes hexadecimal string)
+        msg0 (string): even message (28 hexdigits)
+        msg1 (string): odd message (28 hexdigits)
        t0 (int): timestamps for the even message
        t1 (int): timestamps for the odd message

@@ -103,7 +85,7 @@ def airborne_position_with_ref(msg, lat_ref, lon_ref):
    be with in 180NM of the true position.

    Args:
-        msg (string): even message (28 bytes hexadecimal string)
+        msg (str): even message (28 hexdigits)
        lat_ref: previous known latitude
        lon_ref: previous known longitude

@@ -145,7 +127,7 @@ def altitude(msg):
    """Decode aircraft altitude

    Args:
-        msg (string): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        int: altitude in feet
--- a/pyModeS/decoder/bds/bds06.py
+++ b/pyModeS/decoder/bds/bds06.py
@@ -1,28 +1,10 @@
-# Copyright (C) 2018 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-
 # ------------------------------------------
 #   BDS 0,6
 #   ADS-B TC=5-8
-#   Surface position
+#   Surface movment
 # ------------------------------------------

-from __future__ import absolute_import, print_function, division
-from pyModeS.decoder import common
-import math
+from pyModeS import common


 def surface_position(msg0, msg1, t0, t1, lat_ref, lon_ref):
@@ -30,8 +12,8 @@ def surface_position(msg0, msg1, t0, t1, lat_ref, lon_ref):
    the lat/lon of receiver must be provided to yield the correct solution.

    Args:
-        msg0 (string): even message (28 bytes hexadecimal string)
-        msg1 (string): odd message (28 bytes hexadecimal string)
+        msg0 (string): even message (28 hexdigits)
+        msg1 (string): odd message (28 hexdigits)
        t0 (int): timestamps for the even message
        t1 (int): timestamps for the odd message
        lat_ref (float): latitude of the receiver
@@ -107,7 +89,7 @@ def surface_position_with_ref(msg, lat_ref, lon_ref):
    be with in 45NM of the true position.

    Args:
-        msg (string): even message (28 bytes hexadecimal string)
+        msg (str): even message (28 hexdigits)
        lat_ref: previous known latitude
        lon_ref: previous known longitude

@@ -145,23 +127,24 @@ def surface_position_with_ref(msg, lat_ref, lon_ref):
    return round(lat, 5), round(lon, 5)


-def surface_velocity(msg, rtn_sources=False):
-    """Decode surface velocity from from a surface position message
+def surface_velocity(msg, source=False):
+    """Decode surface velocity from a surface position message
+
    Args:
-        msg (string): 28 bytes hexadecimal message string
-        rtn_source (boolean): If the function will return
-            the sources for direction of travel and vertical
-            rate. This will change the return value from a four
-            element array to a six element array.
+        msg (str): 28 hexdigits string
+        source (boolean): Include direction and vertical rate sources in return. Default to False.
+            If set to True, the function will return six value instead of four.

    Returns:
-        (int, float, int, string, string, None): speed (kt),
-            ground track (degree), None for rate of climb/descend (ft/min),
-            and speed type ('GS' for ground speed), direction source
-            ('true_north' for ground track / true north as reference),
-            None rate of climb/descent source.
-    """
+        int, float, int, string, [string], [string]: Four or six parameters, including:
+            - Speed (kt)
+            - Angle (degree), ground track
+            - Vertical rate, always 0
+            - Speed type ('GS' for ground speed, 'AS' for airspeed)
+            - [Optional] Direction source ('TRUE_NORTH')
+            - [Optional] Vertical rate source (None)

+    """
    if common.typecode(msg) < 5 or common.typecode(msg) > 8:
        raise RuntimeError("%s: Not a surface message, expecting 5<TC<8" % msg)

@@ -175,7 +158,7 @@ def surface_velocity(msg, rtn_sources=False):
    else:
        trk = None

-    # ground movment / speed
+    # ground movement / speed
    mov = common.bin2int(mb[5:12])

    if mov == 0 or mov > 124:
@@ -192,7 +175,7 @@ def surface_velocity(msg, rtn_sources=False):
        spd = kts[i - 1] + (mov - movs[i - 1]) * step
        spd = round(spd, 2)

-    if rtn_sources:
-        return spd, trk, 0, "GS", "true_north", None
+    if source:
+        return spd, trk, 0, "GS", "TRUE_NORTH", None
    else:
        return spd, trk, 0, "GS"
--- a/pyModeS/decoder/bds/bds08.py
+++ b/pyModeS/decoder/bds/bds08.py
@@ -1,34 +1,17 @@
-# Copyright (C) 2018 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-
 # ------------------------------------------
 #   BDS 0,8
 #   ADS-B TC=1-4
 #   Aircraft identitification and category
 # ------------------------------------------

-from __future__ import absolute_import, print_function, division
-from pyModeS.decoder import common
+from pyModeS import common


 def category(msg):
    """Aircraft category number

    Args:
-        msg (string): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        int: category number
@@ -46,7 +29,7 @@ def callsign(msg):
    """Aircraft callsign

    Args:
-        msg (string): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        string: callsign
--- a/pyModeS/decoder/bds/bds09.py
+++ b/pyModeS/decoder/bds/bds09.py
@@ -1,51 +1,33 @@
-# Copyright (C) 2018 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-
 # ------------------------------------------
 #   BDS 0,9
 #   ADS-B TC=19
 #   Aircraft Airborn velocity
 # ------------------------------------------

-from __future__ import absolute_import, print_function, division
-from pyModeS.decoder import common
+from pyModeS import common
+
+
 import math


-def airborne_velocity(msg, rtn_sources=False):
-    """Calculate the speed, track (or heading), and vertical rate
+def airborne_velocity(msg, source=False):
+    """Decode airborne velocity.

    Args:
-        msg (string): 28 bytes hexadecimal message string
-        rtn_source (boolean): If the function will return
-            the sources for direction of travel and vertical
-            rate. This will change the return value from a four
-            element array to a six element array.
+        msg (str): 28 hexdigits string
+        source (boolean): Include direction and vertical rate sources in return. Default to False.
+            If set to True, the function will return six value instead of four.

    Returns:
-        (int, float, int, string, string, string): speed (kt),
-            ground track or heading (degree),
-            rate of climb/descent (ft/min), speed type
-            ('GS' for ground speed, 'AS' for airspeed),
-            direction source ('true_north' for ground track / true north
-            as refrence, 'mag_north' for magnetic north as reference),
-            rate of climb/descent source ('Baro' for barometer, 'GNSS'
-            for GNSS constellation).
-    """
+        int, float, int, string, [string], [string]: Four or six parameters, including:
+            - Speed (kt)
+            - Angle (degree), either ground track or heading
+            - Vertical rate (ft/min)
+            - Speed type ('GS' for ground speed, 'AS' for airspeed)
+            - [Optional] Direction source ('TRUE_NORTH' or 'MAGENTIC_NORTH')
+            - [Optional] Vertical rate source ('BARO' or 'GNSS')

+    """
    if common.typecode(msg) != 19:
        raise RuntimeError("%s: Not a airborne velocity message, expecting TC=19" % msg)

@@ -77,9 +59,9 @@ def airborne_velocity(msg, rtn_sources=False):
        trk = math.degrees(trk)  # convert to degrees
        trk = trk if trk >= 0 else trk + 360  # no negative val

-        tag = "GS"
+        spd_type = "GS"
        trk_or_hdg = round(trk, 2)
-        dir_type = "true_north"
+        dir_type = "TRUE_NORTH"

    else:
        if mb[13] == "0":
@@ -96,32 +78,33 @@ def airborne_velocity(msg, rtn_sources=False):
            spd *= 4

        if mb[24] == "0":
-            tag = "IAS"
+            spd_type = "IAS"
        else:
-            tag = "TAS"
+            spd_type = "TAS"

-        dir_type = "mag_north"
+        dir_type = "MAGENTIC_NORTH"

-    vr_source = "GNSS" if mb[35] == "0" else "Baro"
+    vr_source = "GNSS" if mb[35] == "0" else "BARO"
    vr_sign = -1 if mb[36] == "1" else 1
    vr = common.bin2int(mb[37:46])
-    rocd = None if vr == 0 else int(vr_sign * (vr - 1) * 64)
+    vs = None if vr == 0 else int(vr_sign * (vr - 1) * 64)

-    if rtn_sources:
-        return spd, trk_or_hdg, rocd, tag, dir_type, vr_source
+    if source:
+        return spd, trk_or_hdg, vs, spd_type, dir_type, vr_source
    else:
-        return spd, trk_or_hdg, rocd, tag
+        return spd, trk_or_hdg, vs, spd_type


 def altitude_diff(msg):
-    """Decode the differece between GNSS and barometric altitude
+    """Decode the differece between GNSS and barometric altitude.

    Args:
-        msg (string): 28 bytes hexadecimal message string, TC=19
+        msg (str): 28 hexdigits string, TC=19

    Returns:
-        int: Altitude difference in ft. Negative value indicates GNSS altitude
-            below barometric altitude.
+        int: Altitude difference in feet. Negative value indicates GNSS altitude
+        below barometric altitude.
+
    """
    tc = common.typecode(msg)

--- a/pyModeS/decoder/bds/bds10.py
+++ b/pyModeS/decoder/bds/bds10.py
@@ -1,54 +1,38 @@
-# Copyright (C) 2018 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
 # ------------------------------------------
 # BDS 1,0
 # Data link capability report
 # ------------------------------------------

-from __future__ import absolute_import, print_function, division
-from pyModeS.decoder.common import hex2bin, bin2int, data, allzeros
+from pyModeS import common


 def is10(msg):
    """Check if a message is likely to be BDS code 1,0

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        bool: True or False
    """

-    if allzeros(msg):
+    if common.allzeros(msg):
        return False

-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    # first 8 bits must be 0x10
    if d[0:8] != "00010000":
        return False

    # bit 10 to 14 are reserved
-    if bin2int(d[9:14]) != 0:
+    if common.bin2int(d[9:14]) != 0:
        return False

-    # overlay capabilty conflict
-    if d[14] == "1" and bin2int(d[16:23]) < 5:
+    # overlay capability conflict
+    if d[14] == "1" and common.bin2int(d[16:23]) < 5:
        return False
-    if d[14] == "0" and bin2int(d[16:23]) > 4:
+    if d[14] == "0" and common.bin2int(d[16:23]) > 4:
        return False

    return True
@@ -58,11 +42,11 @@ def ovc10(msg):
    """Return the overlay control capability

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        int: Whether the transponder is OVC capable
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    return int(d[14])
--- a/pyModeS/decoder/bds/bds17.py
+++ b/pyModeS/decoder/bds/bds17.py
@@ -1,45 +1,27 @@
-# Copyright (C) 2018 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-
 # ------------------------------------------
 #   BDS 1,7
 #   Common usage GICB capability report
 # ------------------------------------------

-
-from __future__ import absolute_import, print_function, division
-from pyModeS.decoder.common import hex2bin, bin2int, data, allzeros
+from pyModeS import common


 def is17(msg):
    """Check if a message is likely to be BDS code 1,7

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        bool: True or False
    """

-    if allzeros(msg):
+    if common.allzeros(msg):
        return False

-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

-    if bin2int(d[28:56]) != 0:
+    if common.bin2int(d[28:56]) != 0:
        return False

    caps = cap17(msg)
@@ -60,10 +42,10 @@ def cap17(msg):
    """Extract capacities from BDS 1,7 message

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
-        list: list of suport BDS codes
+        list: list of support BDS codes
    """
    allbds = [
        "05",
@@ -96,7 +78,7 @@ def cap17(msg):
        "E2",
    ]

-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))
    idx = [i for i, v in enumerate(d[:28]) if v == "1"]
    capacity = ["BDS" + allbds[i] for i in idx if allbds[i] is not "NA"]

--- a/pyModeS/decoder/bds/bds20.py
+++ b/pyModeS/decoder/bds/bds20.py
@@ -1,41 +1,25 @@
-# Copyright (C) 2018 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
 # ------------------------------------------
 # BDS 2,0
 # Aircraft identification
 # ------------------------------------------

-from __future__ import absolute_import, print_function, division
-from pyModeS.decoder.common import hex2bin, bin2int, data, allzeros
+from pyModeS import common


 def is20(msg):
    """Check if a message is likely to be BDS code 2,0

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        bool: True or False
    """

-    if allzeros(msg):
+    if common.allzeros(msg):
        return False

-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[0:8] != "00100000":
        return False
@@ -52,23 +36,23 @@ def cs20(msg):
    """Aircraft callsign

    Args:
-        msg (String): 28 bytes hexadecimal message (BDS40) string
+        msg (str): 28 hexdigits string

    Returns:
        string: callsign, max. 8 chars
    """
    chars = "#ABCDEFGHIJKLMNOPQRSTUVWXYZ#####_###############0123456789######"

-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    cs = ""
-    cs += chars[bin2int(d[8:14])]
-    cs += chars[bin2int(d[14:20])]
-    cs += chars[bin2int(d[20:26])]
-    cs += chars[bin2int(d[26:32])]
-    cs += chars[bin2int(d[32:38])]
-    cs += chars[bin2int(d[38:44])]
-    cs += chars[bin2int(d[44:50])]
-    cs += chars[bin2int(d[50:56])]
+    cs += chars[common.bin2int(d[8:14])]
+    cs += chars[common.bin2int(d[14:20])]
+    cs += chars[common.bin2int(d[20:26])]
+    cs += chars[common.bin2int(d[26:32])]
+    cs += chars[common.bin2int(d[32:38])]
+    cs += chars[common.bin2int(d[38:44])]
+    cs += chars[common.bin2int(d[44:50])]
+    cs += chars[common.bin2int(d[50:56])]

    return cs
--- a/pyModeS/decoder/bds/bds30.py
+++ b/pyModeS/decoder/bds/bds30.py
@@ -1,41 +1,25 @@
-# Copyright (C) 2018 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
 # ------------------------------------------
 # BDS 3,0
 # ACAS active resolution advisory
 # ------------------------------------------

-from __future__ import absolute_import, print_function, division
-from pyModeS.decoder.common import hex2bin, bin2int, data, allzeros
+from pyModeS import common


 def is30(msg):
    """Check if a message is likely to be BDS code 2,0

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        bool: True or False
    """

-    if allzeros(msg):
+    if common.allzeros(msg):
        return False

-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[0:8] != "00110000":
        return False
@@ -45,7 +29,7 @@ def is30(msg):
        return False

    # reserved for ACAS III, in far future
-    if bin2int(d[15:22]) >= 48:
+    if common.bin2int(d[15:22]) >= 48:
        return False

    return True
--- a/pyModeS/decoder/bds/bds40.py
+++ b/pyModeS/decoder/bds/bds40.py
@@ -1,66 +1,50 @@
-# Copyright (C) 2018 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
 # ------------------------------------------
 # BDS 4,0
 # Selected vertical intention
 # ------------------------------------------

-from __future__ import absolute_import, print_function, division
 import warnings
-from pyModeS.decoder.common import hex2bin, bin2int, data, allzeros, wrongstatus
+from pyModeS import common


 def is40(msg):
    """Check if a message is likely to be BDS code 4,0

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        bool: True or False
    """

-    if allzeros(msg):
+    if common.allzeros(msg):
        return False

-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    # status bit 1, 14, and 27

-    if wrongstatus(d, 1, 2, 13):
+    if common.wrongstatus(d, 1, 2, 13):
        return False

-    if wrongstatus(d, 14, 15, 26):
+    if common.wrongstatus(d, 14, 15, 26):
        return False

-    if wrongstatus(d, 27, 28, 39):
+    if common.wrongstatus(d, 27, 28, 39):
        return False

-    if wrongstatus(d, 48, 49, 51):
+    if common.wrongstatus(d, 48, 49, 51):
        return False

-    if wrongstatus(d, 54, 55, 56):
+    if common.wrongstatus(d, 54, 55, 56):
        return False

    # bits 40-47 and 52-53 shall all be zero

-    if bin2int(d[39:47]) != 0:
+    if common.bin2int(d[39:47]) != 0:
        return False

-    if bin2int(d[51:53]) != 0:
+    if common.bin2int(d[51:53]) != 0:
        return False

    return True
@@ -70,17 +54,17 @@ def selalt40mcp(msg):
    """Selected altitude, MCP/FCU

    Args:
-        msg (String): 28 bytes hexadecimal message (BDS40) string
+        msg (str): 28 hexdigits string

    Returns:
        int: altitude in feet
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[0] == "0":
        return None

-    alt = bin2int(d[1:13]) * 16  # ft
+    alt = common.bin2int(d[1:13]) * 16  # ft
    return alt


@@ -88,17 +72,17 @@ def selalt40fms(msg):
    """Selected altitude, FMS

    Args:
-        msg (String): 28 bytes hexadecimal message (BDS40) string
+        msg (str): 28 hexdigits string

    Returns:
        int: altitude in feet
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[13] == "0":
        return None

-    alt = bin2int(d[14:26]) * 16  # ft
+    alt = common.bin2int(d[14:26]) * 16  # ft
    return alt


@@ -106,17 +90,17 @@ def p40baro(msg):
    """Barometric pressure setting

    Args:
-        msg (String): 28 bytes hexadecimal message (BDS40) string
+        msg (str): 28 hexdigits string

    Returns:
        float: pressure in millibar
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[26] == "0":
        return None

-    p = bin2int(d[27:39]) * 0.1 + 800  # millibar
+    p = common.bin2int(d[27:39]) * 0.1 + 800  # millibar
    return p


--- a/pyModeS/decoder/bds/bds44.py
+++ b/pyModeS/decoder/bds/bds44.py
@@ -1,25 +1,9 @@
-# Copyright (C) 2018 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
 # ------------------------------------------
 # BDS 4,4
 # Meteorological routine air report
 # ------------------------------------------

-from __future__ import absolute_import, print_function, division
-from pyModeS.decoder.common import hex2bin, bin2int, data, allzeros, wrongstatus
+from pyModeS import common


 def is44(msg):
@@ -28,32 +12,32 @@ def is44(msg):
    Meteorological routine air report

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        bool: True or False

    """
-    if allzeros(msg):
+    if common.allzeros(msg):
        return False

-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    # status bit 5, 35, 47, 50
-    if wrongstatus(d, 5, 6, 23):
+    if common.wrongstatus(d, 5, 6, 23):
        return False

-    if wrongstatus(d, 35, 36, 46):
+    if common.wrongstatus(d, 35, 36, 46):
        return False

-    if wrongstatus(d, 47, 48, 49):
+    if common.wrongstatus(d, 47, 48, 49):
        return False

-    if wrongstatus(d, 50, 51, 56):
+    if common.wrongstatus(d, 50, 51, 56):
        return False

    # Bits 1-4 indicate source, values > 4 reserved and should not occur
-    if bin2int(d[0:4]) > 4:
+    if common.bin2int(d[0:4]) > 4:
        return False

    vw, dw = wind44(msg)
@@ -71,20 +55,20 @@ def wind44(msg):
    """Wind speed and direction.

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        (int, float): speed (kt), direction (degree)

    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    status = int(d[4])
    if not status:
        return None, None

-    speed = bin2int(d[5:14])  # knots
-    direction = bin2int(d[14:23]) * 180.0 / 256.0  # degree
+    speed = common.bin2int(d[5:14])  # knots
+    direction = common.bin2int(d[14:23]) * 180.0 / 256.0  # degree

    return round(speed, 0), round(direction, 1)

@@ -93,18 +77,18 @@ def temp44(msg):
    """Static air temperature.

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        float, float: temperature and alternative temperature in Celsius degree.
-            Note: Two values returns due to what seems to be an inconsistancy
+            Note: Two values returns due to what seems to be an inconsistency
            error in ICAO 9871 (2008) Appendix A-67.

    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    sign = int(d[23])
-    value = bin2int(d[24:34])
+    value = common.bin2int(d[24:34])

    if sign:
        value = value - 1024
@@ -122,18 +106,18 @@ def p44(msg):
    """Static pressure.

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        int: static pressure in hPa

    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[34] == "0":
        return None

-    p = bin2int(d[35:46])  # hPa
+    p = common.bin2int(d[35:46])  # hPa

    return p

@@ -142,17 +126,17 @@ def hum44(msg):
    """humidity

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        float: percentage of humidity, [0 - 100] %
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[49] == "0":
        return None

-    hm = bin2int(d[50:56]) * 100.0 / 64  # %
+    hm = common.bin2int(d[50:56]) * 100.0 / 64  # %

    return round(hm, 1)

@@ -161,17 +145,17 @@ def turb44(msg):
    """Turblence.

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        int: turbulence level. 0=NIL, 1=Light, 2=Moderate, 3=Severe

    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[46] == "0":
        return None

-    turb = bin2int(d[47:49])
+    turb = common.bin2int(d[47:49])

    return turb
--- a/pyModeS/decoder/bds/bds45.py
+++ b/pyModeS/decoder/bds/bds45.py
@@ -1,25 +1,9 @@
-# Copyright (C) 2018 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
 # ------------------------------------------
 # BDS 4,5
 # Meteorological hazard report
 # ------------------------------------------

-from __future__ import absolute_import, print_function, division
-from pyModeS.decoder.common import hex2bin, bin2int, data, allzeros, wrongstatus
+from pyModeS import common


 def is45(msg):
@@ -28,44 +12,44 @@ def is45(msg):
    Meteorological hazard report

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        bool: True or False

    """
-    if allzeros(msg):
+    if common.allzeros(msg):
        return False

-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    # status bit 1, 4, 7, 10, 13, 16, 27, 39
-    if wrongstatus(d, 1, 2, 3):
+    if common.wrongstatus(d, 1, 2, 3):
        return False

-    if wrongstatus(d, 4, 5, 6):
+    if common.wrongstatus(d, 4, 5, 6):
        return False

-    if wrongstatus(d, 7, 8, 9):
+    if common.wrongstatus(d, 7, 8, 9):
        return False

-    if wrongstatus(d, 10, 11, 12):
+    if common.wrongstatus(d, 10, 11, 12):
        return False

-    if wrongstatus(d, 13, 14, 15):
+    if common.wrongstatus(d, 13, 14, 15):
        return False

-    if wrongstatus(d, 16, 17, 26):
+    if common.wrongstatus(d, 16, 17, 26):
        return False

-    if wrongstatus(d, 27, 28, 38):
+    if common.wrongstatus(d, 27, 28, 38):
        return False

-    if wrongstatus(d, 39, 40, 51):
+    if common.wrongstatus(d, 39, 40, 51):
        return False

    # reserved
-    if bin2int(d[51:56]) != 0:
+    if common.bin2int(d[51:56]) != 0:
        return False

    temp = temp45(msg)
@@ -80,17 +64,17 @@ def turb45(msg):
    """Turbulence.

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        int: Turbulence level. 0=NIL, 1=Light, 2=Moderate, 3=Severe

    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))
    if d[0] == "0":
        return None

-    turb = bin2int(d[1:3])
+    turb = common.bin2int(d[1:3])
    return turb


@@ -98,17 +82,17 @@ def ws45(msg):
    """Wind shear.

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        int: Wind shear level. 0=NIL, 1=Light, 2=Moderate, 3=Severe

    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))
    if d[3] == "0":
        return None

-    ws = bin2int(d[4:6])
+    ws = common.bin2int(d[4:6])
    return ws


@@ -116,17 +100,17 @@ def mb45(msg):
    """Microburst.

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        int: Microburst level. 0=NIL, 1=Light, 2=Moderate, 3=Severe

    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))
    if d[6] == "0":
        return None

-    mb = bin2int(d[7:9])
+    mb = common.bin2int(d[7:9])
    return mb


@@ -134,17 +118,17 @@ def ic45(msg):
    """Icing.

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        int: Icing level. 0=NIL, 1=Light, 2=Moderate, 3=Severe

    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))
    if d[9] == "0":
        return None

-    ic = bin2int(d[10:12])
+    ic = common.bin2int(d[10:12])
    return ic


@@ -152,17 +136,17 @@ def wv45(msg):
    """Wake vortex.

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        int: Wake vortex level. 0=NIL, 1=Light, 2=Moderate, 3=Severe

    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))
    if d[12] == "0":
        return None

-    ws = bin2int(d[13:15])
+    ws = common.bin2int(d[13:15])
    return ws


@@ -170,16 +154,16 @@ def temp45(msg):
    """Static air temperature.

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        float: tmeperature in Celsius degree

    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    sign = int(d[16])
-    value = bin2int(d[17:26])
+    value = common.bin2int(d[17:26])

    if sign:
        value = value - 512
@@ -194,16 +178,16 @@ def p45(msg):
    """Average static pressure.

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        int: static pressure in hPa

    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))
    if d[26] == "0":
        return None
-    p = bin2int(d[27:38])  # hPa
+    p = common.bin2int(d[27:38])  # hPa
    return p


@@ -211,14 +195,14 @@ def rh45(msg):
    """Radio height.

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        int: radio height in ft

    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))
    if d[38] == "0":
        return None
-    rh = bin2int(d[39:51]) * 16
+    rh = common.bin2int(d[39:51]) * 16
    return rh
--- a/pyModeS/decoder/bds/bds50.py
+++ b/pyModeS/decoder/bds/bds50.py
@@ -1,25 +1,9 @@
-# Copyright (C) 2018 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
 # ------------------------------------------
 # BDS 5,0
 # Track and turn report
 # ------------------------------------------

-from __future__ import absolute_import, print_function, division
-from pyModeS.decoder.common import hex2bin, bin2int, data, allzeros, wrongstatus
+from pyModeS import common


 def is50(msg):
@@ -27,32 +11,32 @@ def is50(msg):
    (Track and turn report)

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        bool: True or False
    """

-    if allzeros(msg):
+    if common.allzeros(msg):
        return False

-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    # status bit 1, 12, 24, 35, 46

-    if wrongstatus(d, 1, 3, 11):
+    if common.wrongstatus(d, 1, 3, 11):
        return False

-    if wrongstatus(d, 12, 13, 23):
+    if common.wrongstatus(d, 12, 13, 23):
        return False

-    if wrongstatus(d, 24, 25, 34):
+    if common.wrongstatus(d, 24, 25, 34):
        return False

-    if wrongstatus(d, 35, 36, 45):
+    if common.wrongstatus(d, 35, 36, 45):
        return False

-    if wrongstatus(d, 46, 47, 56):
+    if common.wrongstatus(d, 46, 47, 56):
        return False

    roll = roll50(msg)
@@ -77,19 +61,19 @@ def roll50(msg):
    """Roll angle, BDS 5,0 message

    Args:
-        msg (String): 28 bytes hexadecimal message (BDS50) string
+        msg (str): 28 hexdigits string

    Returns:
        float: angle in degrees,
               negative->left wing down, positive->right wing down
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[0] == "0":
        return None

    sign = int(d[1])  # 1 -> left wing down
-    value = bin2int(d[2:11])
+    value = common.bin2int(d[2:11])

    if sign:
        value = value - 512
@@ -102,18 +86,18 @@ def trk50(msg):
    """True track angle, BDS 5,0 message

    Args:
-        msg (String): 28 bytes hexadecimal message (BDS50) string
+        msg (str): 28 hexdigits string

    Returns:
        float: angle in degrees to true north (from 0 to 360)
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[11] == "0":
        return None

    sign = int(d[12])  # 1 -> west
-    value = bin2int(d[13:23])
+    value = common.bin2int(d[13:23])

    if sign:
        value = value - 1024
@@ -131,17 +115,17 @@ def gs50(msg):
    """Ground speed, BDS 5,0 message

    Args:
-        msg (String): 28 bytes hexadecimal message (BDS50) string
+        msg (str): 28 hexdigits string

    Returns:
        int: ground speed in knots
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[23] == "0":
        return None

-    spd = bin2int(d[24:34]) * 2  # kts
+    spd = common.bin2int(d[24:34]) * 2  # kts
    return spd


@@ -149,12 +133,12 @@ def rtrk50(msg):
    """Track angle rate, BDS 5,0 message

    Args:
-        msg (String): 28 bytes hexadecimal message (BDS50) string
+        msg (str): 28 hexdigits string

    Returns:
        float: angle rate in degrees/second
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[34] == "0":
        return None
@@ -163,7 +147,7 @@ def rtrk50(msg):
        return None

    sign = int(d[35])  # 1 -> negative value, two's complement
-    value = bin2int(d[36:45])
+    value = common.bin2int(d[36:45])
    if sign:
        value = value - 512

@@ -175,15 +159,15 @@ def tas50(msg):
    """Aircraft true airspeed, BDS 5,0 message

    Args:
-        msg (String): 28 bytes hexadecimal message (BDS50) string
+        msg (str): 28 hexdigits string

    Returns:
        int: true airspeed in knots
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[45] == "0":
        return None

-    tas = bin2int(d[46:56]) * 2  # kts
+    tas = common.bin2int(d[46:56]) * 2  # kts
    return tas
--- a/pyModeS/decoder/bds/bds53.py
+++ b/pyModeS/decoder/bds/bds53.py
@@ -1,25 +1,9 @@
-# Copyright (C) 2018 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
 # ------------------------------------------
 # BDS 5,3
 # Air-referenced state vector
 # ------------------------------------------

-from __future__ import absolute_import, print_function, division
-from pyModeS.decoder.common import hex2bin, bin2int, data, allzeros, wrongstatus
+from pyModeS import common


 def is53(msg):
@@ -27,32 +11,32 @@ def is53(msg):
    (Air-referenced state vector)

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        bool: True or False
    """

-    if allzeros(msg):
+    if common.allzeros(msg):
        return False

-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    # status bit 1, 13, 24, 34, 47

-    if wrongstatus(d, 1, 3, 12):
+    if common.wrongstatus(d, 1, 3, 12):
        return False

-    if wrongstatus(d, 13, 14, 23):
+    if common.wrongstatus(d, 13, 14, 23):
        return False

-    if wrongstatus(d, 24, 25, 33):
+    if common.wrongstatus(d, 24, 25, 33):
        return False

-    if wrongstatus(d, 34, 35, 46):
+    if common.wrongstatus(d, 34, 35, 46):
        return False

-    if wrongstatus(d, 47, 49, 56):
+    if common.wrongstatus(d, 47, 49, 56):
        return False

    ias = ias53(msg)
@@ -78,18 +62,18 @@ def hdg53(msg):
    """Magnetic heading, BDS 5,3 message

    Args:
-        msg (String): 28 bytes hexadecimal message (BDS53) string
+        msg (str): 28 hexdigits string

    Returns:
        float: angle in degrees to true north (from 0 to 360)
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[0] == "0":
        return None

    sign = int(d[1])  # 1 -> west
-    value = bin2int(d[2:12])
+    value = common.bin2int(d[2:12])

    if sign:
        value = value - 1024
@@ -107,17 +91,17 @@ def ias53(msg):
    """Indicated airspeed, DBS 5,3 message

    Args:
-        msg (String): 28 bytes hexadecimal message
+        msg (str): 28 hexdigits

    Returns:
        int: indicated arispeed in knots
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[12] == "0":
        return None

-    ias = bin2int(d[13:23])  # knots
+    ias = common.bin2int(d[13:23])  # knots
    return ias


@@ -125,17 +109,17 @@ def mach53(msg):
    """MACH number, DBS 5,3 message

    Args:
-        msg (String): 28 bytes hexadecimal message
+        msg (str): 28 hexdigits

    Returns:
        float: MACH number
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[23] == "0":
        return None

-    mach = bin2int(d[24:33]) * 0.008
+    mach = common.bin2int(d[24:33]) * 0.008
    return round(mach, 3)


@@ -143,17 +127,17 @@ def tas53(msg):
    """Aircraft true airspeed, BDS 5,3 message

    Args:
-        msg (String): 28 bytes hexadecimal message
+        msg (str): 28 hexdigits

    Returns:
        float: true airspeed in knots
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[33] == "0":
        return None

-    tas = bin2int(d[34:46]) * 0.5  # kts
+    tas = common.bin2int(d[34:46]) * 0.5  # kts
    return round(tas, 1)


@@ -161,18 +145,18 @@ def vr53(msg):
    """Vertical rate

    Args:
-        msg (String): 28 bytes hexadecimal message (BDS60) string
+        msg (str): 28 hexdigits (BDS60) string

    Returns:
        int: vertical rate in feet/minutes
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[46] == "0":
        return None

    sign = int(d[47])  # 1 -> negative value, two's complement
-    value = bin2int(d[48:56])
+    value = common.bin2int(d[48:56])

    if value == 0 or value == 255:  # all zeros or all ones
        return 0
--- a/pyModeS/decoder/bds/bds60.py
+++ b/pyModeS/decoder/bds/bds60.py
@@ -1,57 +1,41 @@
-# Copyright (C) 2018 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
 # ------------------------------------------
 # BDS 6,0
 # Heading and speed report
 # ------------------------------------------

-from __future__ import absolute_import, print_function, division
-from pyModeS.decoder.common import hex2bin, bin2int, data, allzeros, wrongstatus
+from pyModeS import common


 def is60(msg):
    """Check if a message is likely to be BDS code 6,0

    Args:
-        msg (String): 28 bytes hexadecimal message string
+        msg (str): 28 hexdigits string

    Returns:
        bool: True or False
    """

-    if allzeros(msg):
+    if common.allzeros(msg):
        return False

-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    # status bit 1, 13, 24, 35, 46

-    if wrongstatus(d, 1, 2, 12):
+    if common.wrongstatus(d, 1, 2, 12):
        return False

-    if wrongstatus(d, 13, 14, 23):
+    if common.wrongstatus(d, 13, 14, 23):
        return False

-    if wrongstatus(d, 24, 25, 34):
+    if common.wrongstatus(d, 24, 25, 34):
        return False

-    if wrongstatus(d, 35, 36, 45):
+    if common.wrongstatus(d, 35, 36, 45):
        return False

-    if wrongstatus(d, 46, 47, 56):
+    if common.wrongstatus(d, 46, 47, 56):
        return False

    ias = ias60(msg)
@@ -77,18 +61,18 @@ def hdg60(msg):
    """Megnetic heading of aircraft

    Args:
-        msg (String): 28 bytes hexadecimal message (BDS60) string
+        msg (str): 28 hexdigits string

    Returns:
        float: heading in degrees to megnetic north (from 0 to 360)
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[0] == "0":
        return None

    sign = int(d[1])  # 1 -> west
-    value = bin2int(d[2:12])
+    value = common.bin2int(d[2:12])

    if sign:
        value = value - 1024
@@ -106,17 +90,17 @@ def ias60(msg):
    """Indicated airspeed

    Args:
-        msg (String): 28 bytes hexadecimal message (BDS60) string
+        msg (str): 28 hexdigits string

    Returns:
        int: indicated airspeed in knots
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[12] == "0":
        return None

-    ias = bin2int(d[13:23])  # kts
+    ias = common.bin2int(d[13:23])  # kts
    return ias


@@ -124,17 +108,17 @@ def mach60(msg):
    """Aircraft MACH number

    Args:
-        msg (String): 28 bytes hexadecimal message (BDS60) string
+        msg (str): 28 hexdigits string

    Returns:
        float: MACH number
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[23] == "0":
        return None

-    mach = bin2int(d[24:34]) * 2.048 / 512.0
+    mach = common.bin2int(d[24:34]) * 2.048 / 512.0
    return round(mach, 3)


@@ -142,18 +126,18 @@ def vr60baro(msg):
    """Vertical rate from barometric measurement, this value may be very noisy.

    Args:
-        msg (String): 28 bytes hexadecimal message (BDS60) string
+        msg (str): 28 hexdigits string

    Returns:
        int: vertical rate in feet/minutes
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[34] == "0":
        return None

    sign = int(d[35])  # 1 -> negative value, two's complement
-    value = bin2int(d[36:45])
+    value = common.bin2int(d[36:45])

    if value == 0 or value == 511:  # all zeros or all ones
        return 0
@@ -165,21 +149,21 @@ def vr60baro(msg):


 def vr60ins(msg):
-    """Vertical rate messured by onbard equiments (IRS, AHRS)
+    """Vertical rate measurd by onbard equiments (IRS, AHRS)

    Args:
-        msg (String): 28 bytes hexadecimal message (BDS60) string
+        msg (str): 28 hexdigits string

    Returns:
        int: vertical rate in feet/minutes
    """
-    d = hex2bin(data(msg))
+    d = common.hex2bin(common.data(msg))

    if d[45] == "0":
        return None

    sign = int(d[46])  # 1 -> negative value, two's complement
-    value = bin2int(d[47:56])
+    value = common.bin2int(d[47:56])

    if value == 0 or value == 511:  # all zeros or all ones
        return 0
--- a/pyModeS/decoder/commb.py
+++ b/pyModeS/decoder/commb.py
@@ -1,26 +1,27 @@
-"""Comm-B Wrapper.
+"""Comm-B module.

-The Comm-B wrapper imports all functions from the following modules:
+The Comm-B module imports all functions from the following modules:

-**ELS - elementary surveillance**
-    - pyModeS.decoder.bds.bds10
-    - pyModeS.decoder.bds.bds17
-    - pyModeS.decoder.bds.bds20
-    - pyModeS.decoder.bds.bds30
+ELS - elementary surveillance

-**EHS - enhanced surveillance**
-    - pyModeS.decoder.bds.bds40
-    - pyModeS.decoder.bds.bds50
-    - pyModeS.decoder.bds.bds60
+- pyModeS.decoder.bds.bds10
+- pyModeS.decoder.bds.bds17
+- pyModeS.decoder.bds.bds20
+- pyModeS.decoder.bds.bds30

-**MRAR and MHR**
-    - pyModeS.decoder.bds.bds44
-    - pyModeS.decoder.bds.bds45
+EHS - enhanced surveillance
+
+- pyModeS.decoder.bds.bds40
+- pyModeS.decoder.bds.bds50
+- pyModeS.decoder.bds.bds60
+
+MRAR and MHR
+
+- pyModeS.decoder.bds.bds44
+- pyModeS.decoder.bds.bds45

 """

-from __future__ import absolute_import, print_function, division
-
 # ELS - elementary surveillance
 from pyModeS.decoder.bds.bds10 import *
 from pyModeS.decoder.bds.bds17 import *
--- a/pyModeS/decoder/ehs.py
+++ b/pyModeS/decoder/ehs.py
@@ -9,7 +9,6 @@ The EHS wrapper imports all functions from the following modules:

 """

-from __future__ import absolute_import, print_function, division
 import warnings

 from pyModeS.decoder.bds.bds40 import *
--- a/pyModeS/decoder/els.py
+++ b/pyModeS/decoder/els.py
@@ -10,8 +10,6 @@ The ELS wrapper imports all functions from the following modules:

 """

-from __future__ import absolute_import, print_function, division
-
 from pyModeS.decoder.bds.bds10 import *
 from pyModeS.decoder.bds.bds17 import *
 from pyModeS.decoder.bds.bds20 import *
--- a/pyModeS/decoder/surv.py
+++ b/pyModeS/decoder/surv.py
@@ -1,23 +1,5 @@
-# Copyright (C) 2018 Junzi Sun (TU Delft)
-
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
 """
 Warpper for short roll call surveillance replies DF=4/5

 [To be implemented]
 """
-
-from __future__ import absolute_import, print_function, division
-from pyModeS.decoder import common
--- a/pyModeS/decoder/uplink.py
+++ b/pyModeS/decoder/uplink.py
@@ -0,0 +1,25 @@
+from pyModeS import common
+
+
+def uplink_icao(msg):
+    """Calculate the ICAO address from a Mode-S interrogation (uplink message)"""
+    p_gen = 0xFFFA0480 << ((len(msg) - 14) * 4)
+    data = int(msg[:-6], 16)
+    PA = int(msg[-6:], 16)
+    ad = 0
+    topbit = 0b1 << (len(msg) * 4 - 25)
+    for j in range(0, len(msg) * 4, 1):
+        if data & topbit:
+            data ^= p_gen
+        data = (data << 1) + ((PA >> 23) & 1)
+        PA = PA << 1
+        if j > (len(msg) * 4 - 26):
+            ad = ad + ((data >> (len(msg) * 4 - 25)) & 1)
+            ad = ad << 1
+    return "%06X" % (ad >> 2)
+
+
+def uf(msg):
+    """Decode Uplink Format value, bits 1 to 5."""
+    ufbin = common.hex2bin(msg[:2])
+    return min(common.bin2int(ufbin[0:5]), 24)
--- a/pyModeS/encoder/init.py
+++ b/pyModeS/encoder/init.py
@@ -0,0 +1,68 @@
+from .bds.bds08 import me08
+from .bds.bds09 import me09
+from pyModeS import common
+
+
+def encode_adsb(**kwargs):
+    """Encode ADS-B message.
+
+    Args:
+        icao (string): Transponder ICAO address (6 hexdigits)
+        capability (int): Transponder capability, between 0 and 7
+        typecode (int): Typecode, less than 32
+
+        callsign (string): Callsign (6 hexdigits)
+        category (int): Aircraft category, between 0 and 7, Default to 0.
+
+        speed (int): Speed in knots.
+        angle (float): Track angle or heading angle in degrees.
+        vertical_rate (int): vertical rate in feet/minute
+        intent_change (int): Intent change flag, 0 or 1. Default to 0.
+        ifr_capability (int): IFR capability flag, 0 or 1. Default to 1.
+        navigation_quality (int): NUC (ver 0) or NACv (ver 1, 2), between 0 and 7.
+            Default to 0.
+        supersonic (bool): Is this a supersonic flight? Default to False.
+        speed_type (str): Speed type: GS, IAS, or TAS. Default to GS.
+        vertical_rate_source (str): GNSS or BARO. Default to BARO.
+        gnss_baro_alt_diff (int): Different between GNSS and barometric altitude in feet.
+            Negative value indicates GNSS altitude below barometric altitude. Default to 0
+
+    Returns:
+        string: 28 hexdigits raw message
+
+    """
+    tc = kwargs.get("typecode")
+
+    if 1 <= tc <= 4:
+        me = me08(**kwargs)
+    elif tc == 19:
+        me = me09(**kwargs)
+
+    msg = _constuct(**dict(kwargs, me=me))
+    return msg
+
+
+def _constuct(**kwargs):
+    icao = kwargs.get("icao")
+    me = kwargs.get("me")
+    capability = kwargs.get("capability", 6)
+
+    if icao is None or len(icao) != 6:
+        raise Exception("Transponder address must be 6 hexadecimal characters.")
+
+    if me is None or len(me) != 14:
+        raise Exception("Message be 14 hexadecimal characters.")
+
+    if capability > 6:
+        raise Exception("Transponder capability must be smaller than 7.")
+
+    header_bin = "10001" + "{0:03b}".format(capability)
+    header_hex = "{0:02X}".format(int(header_bin, 2))
+
+    msg = header_hex + icao + me + "000000"
+
+    pi = common.crc(msg, encode=True)
+    pi_hex = "{0:06X}".format(pi)
+
+    msg = msg[:-6] + pi_hex
+    return msg
--- a/pyModeS/encoder/bds/init.py
+++ b/pyModeS/encoder/bds/init.py
--- a/pyModeS/encoder/bds/bds05.py
+++ b/pyModeS/encoder/bds/bds05.py
@@ -0,0 +1,5 @@
+# ------------------------------------------
+#   BDS 0,5
+#   ADS-B TC=9-18
+#   Airborn position
+# ------------------------------------------
--- a/pyModeS/encoder/bds/bds06.py
+++ b/pyModeS/encoder/bds/bds06.py
@@ -0,0 +1,5 @@
+# ------------------------------------------
+#   BDS 0,6
+#   ADS-B TC=5-8
+#   Surface position
+# ------------------------------------------
--- a/pyModeS/encoder/bds/bds08.py
+++ b/pyModeS/encoder/bds/bds08.py
@@ -0,0 +1,40 @@
+# ------------------------------------------
+#   BDS 0,8
+#   ADS-B TC=1-4
+#   Aircraft identitification and category
+# ------------------------------------------
+
+from pyModeS import common
+
+charmap = "#ABCDEFGHIJKLMNOPQRSTUVWXYZ##### ###############0123456789######"
+
+
+def me08(callsign, **kwargs):
+    cs = callsign
+    tc = kwargs.get("typecode")
+    cat = kwargs.get("category", 0)
+
+    if len(cs) > 8:
+        raise Exception("callsign must contain less than 9 characters")
+
+    if tc > 4:
+        raise Exception("typecode must be less 5")
+
+    if cat > 7:
+        raise Exception("category must be less 8")
+
+    if not cs.isalnum():
+        raise Exception("callsign must only contain alphanumeric characters")
+
+    cs = "{:<8}".format(cs.upper())
+
+    idx = [charmap.index(c) for c in cs]
+    me_bin = (
+        "{0:05b}".format(tc)
+        + "{0:03b}".format(cat)
+        + "".join("{0:06b}".format(i) for i in idx)
+    )
+
+    me_hex = "{0:04X}".format(int(me_bin, 2))
+
+    return me_hex
--- a/pyModeS/encoder/bds/bds09.py
+++ b/pyModeS/encoder/bds/bds09.py
@@ -0,0 +1,119 @@
+# ------------------------------------------
+#   BDS 0,9
+#   ADS-B TC=19
+#   Aircraft Airborn velocity
+# ------------------------------------------
+
+import numpy as np
+
+
+def me09(speed, angle, vertical_rate, **kwargs):
+    spd = speed
+    agl = angle
+    vr = vertical_rate
+
+    tc = kwargs.get("typecode")
+    intent = kwargs.get("intent_change", 0)
+    ifr = kwargs.get("ifr_capability", 1)
+    navq = kwargs.get("navigation_quality", 0)
+    supersonic = kwargs.get("supersonic", False)
+    spd_type = kwargs.get("speed_type", "gs").lower()
+    vr_source = kwargs.get("vertical_rate_source", "baro").lower()
+    alt_diff = kwargs.get("gnss_baro_alt_diff", 0)
+
+    if tc != 19:
+        raise Exception("Typecode must be 19.")
+
+    if intent not in (0, 1):
+        raise Exception("Intent change flag must be 0 or 1.")
+
+    if ifr not in (0, 1):
+        raise Exception("IFR capability flag must be 0 or 1.")
+
+    if type(supersonic) != bool:
+        raise Exception("Subsonic flag must be True or False.")
+
+    if navq > 7:
+        raise Exception("Navigation quality indicator must be smaller than 8.")
+
+    if spd_type not in ["gs", "tas"]:
+        raise Exception("Speed type must be 'gs', 'ias', or 'tas'.")
+
+    if vr_source not in ["baro", "gnss"]:
+        raise Exception("Vertical rate source must be 'baro' or 'gnss'.")
+
+    me_bin = ""
+
+    # typecode
+    me_bin += "{0:05b}".format(tc)
+
+    # sub-type
+    if supersonic:
+        if spd_type == "gs":
+            me_bin += "010"
+        else:
+            me_bin += "100"
+    else:
+        if spd_type == "gs":
+            me_bin += "001"
+        else:
+            me_bin += "011"
+
+    # intent, ifr, navigation quality
+    me_bin += str(intent) + str(ifr) + "{0:03b}".format(navq)
+
+    # speed and angle part
+    if spd_type == "gs":
+        vx = spd * np.sin(np.radians(agl))
+        vy = spd * np.cos(np.radians(agl))
+
+        if supersonic:
+            vx /= 4
+            vy /= 4
+
+        vx = int(round(vx))
+        vy = int(round(vy))
+
+        sew = "0" if vx >= 0 else "1"
+        sns = "0" if vy >= 0 else "1"
+        vew = "{0:010b}".format(min(abs(vx), 1023) + 1)
+        vns = "{0:010b}".format(min(abs(vy), 1023) + 1)
+
+        me_bin += sew + vew + sns + vns
+
+    elif spd_type == "ias" or spd_type == "tas":
+        hdg = int(round(agl * 1024 / 360))
+        hdg = min(hdg, 1023)
+
+        air_type = "1" if spd_type == "tas" else "0"
+
+        if supersonic:
+            spd /= 4
+
+        spd = min(int(round(spd)), 1023)
+
+        me_bin += "1" + "{0:010b}".format(hdg) + air_type + "{0:010b}".format(spd)
+
+    # vertical rate source
+    me_bin += "1" if vr_source == "baro" else "0"
+
+    # vertical rate
+    me_bin += "0" if vr > 0 else "1"
+    vr = int(round((abs(vr) / 64 + 1)))
+    vr = min(vr, 511)
+    me_bin += "{0:09b}".format(vr)
+
+    # reserved
+    me_bin += "00"
+
+    # altitude difference
+    me_bin += "1" if alt_diff < 0 else "0"
+    alt_diff = int(round(abs(alt_diff) / 25 + 1))
+    alt_diff = min(alt_diff, 127)
+    me_bin += "{0:07b}".format(alt_diff)
+    print(me_bin)
+
+    # convert to hexdigits
+    me_hex = "{0:04X}".format(int(me_bin, 2))
+
+    return me_hex
--- a/pyModeS/extra/init.py
+++ b/pyModeS/extra/init.py
@@ -1 +0,0 @@
-from __future__ import absolute_import, print_function, division
--- a/pyModeS/extra/aero.py
+++ b/pyModeS/extra/aero.py
@@ -9,9 +9,9 @@ International Standard Atmosphere

    p,rho,T = atmos(H)    # atmos as function of geopotential altitude H [m]
    a = vsound(H)         # speed of sound [m/s] as function of H[m]
-    p = pressure(H)       # calls atmos but retruns only pressure [Pa]
+    p = pressure(H)       # calls atmos but returns only pressure [Pa]
    T = temperature(H)    # calculates temperature [K]
-    rho = density(H)      # calls atmos but retruns only pressure [Pa]
+    rho = density(H)      # calls atmos but returns only pressure [Pa]

 Speed conversion at altitude H[m] in ISA
 ::
--- a/pyModeS/extra/rtlreader.py
+++ b/pyModeS/extra/rtlreader.py
@@ -1,90 +1,112 @@
+import traceback
 import numpy as np
 import pyModeS as pms
 from rtlsdr import RtlSdr
 import time

-modes_sample_rate = 2e6
+sampling_rate = 2e6
+smaples_per_microsec = 2
+
 modes_frequency = 1090e6
-buffer_size = 1024 * 100
-read_size = 1024 * 20
+buffer_size = 1024 * 200
+read_size = 1024 * 100

 pbits = 8
 fbits = 112
 preamble = [1, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0]
-th_amp = 0.2  # signal amplitude threshold for 0 and 1 bit
 th_amp_diff = 0.8  # signal amplitude threshold difference between 0 and 1 bit


 class RtlReader(object):
    def __init__(self, **kwargs):
        super(RtlReader, self).__init__()
-        self.signal_buffer = []
+        self.signal_buffer = []  # amplitude of the sample only
        self.sdr = RtlSdr()
-        self.sdr.sample_rate = modes_sample_rate
+        self.sdr.sample_rate = sampling_rate
        self.sdr.center_freq = modes_frequency
        self.sdr.gain = "auto"
-        # sdr.freq_correction = 75

        self.debug = kwargs.get("debug", False)
        self.raw_pipe_in = None
        self.stop_flag = False
+        self.noise_floor = 1e6
+
+    def _calc_noise(self):
+        """Calculate noise floor"""
+        window = smaples_per_microsec * 100
+        total_len = len(self.signal_buffer)
+        means = (
+            np.array(self.signal_buffer[: total_len // window * window])
+            .reshape(-1, window)
+            .mean(axis=1)
+        )
+        return min(means)

    def _process_buffer(self):
+        """process raw IQ data in the buffer"""
+
+        # update noise floor
+        self.noise_floor = min(self._calc_noise(), self.noise_floor)
+
+        # set minimum signal amplitude
+        min_sig_amp = 3.162 * self.noise_floor  # 10 dB SNR
+
+        # Mode S messages
        messages = []

-        # signal_array = np.array(self.signal_buffer)
-        # pulses_array = np.where(np.array(self.signal_buffer) < th_amp, 0, 1)
-        # pulses = "".join(str(x) for x in pulses_array)
        buffer_length = len(self.signal_buffer)

        i = 0
        while i < buffer_length:
-            if self.signal_buffer[i] < th_amp:
+            if self.signal_buffer[i] < min_sig_amp:
                i += 1
                continue

-            # if pulses[i : i + pbits * 2] == preamble:
            if self._check_preamble(self.signal_buffer[i : i + pbits * 2]):
                frame_start = i + pbits * 2
                frame_end = i + pbits * 2 + (fbits + 1) * 2
                frame_length = (fbits + 1) * 2
                frame_pulses = self.signal_buffer[frame_start:frame_end]

-                msgbin = ""
+                threshold = max(frame_pulses) * 0.2
+
+                msgbin = []
                for j in range(0, frame_length, 2):
                    p2 = frame_pulses[j : j + 2]
                    if len(p2) < 2:
                        break

-                    if p2[0] < th_amp and p2[1] < th_amp:
+                    if p2[0] < threshold and p2[1] < threshold:
                        break
                    elif p2[0] >= p2[1]:
-                        c = "1"
+                        c = 1
                    elif p2[0] < p2[1]:
-                        c = "0"
+                        c = 0
                    else:
-                        msgbin = ""
+                        msgbin = []
                        break
-                    msgbin += c
+
+                    msgbin.append(c)

                # advance i with a jump
                i = frame_start + j

                if len(msgbin) > 0:
-                    msghex = pms.bin2hex(msgbin)
+                    msghex = pms.bin2hex("".join([str(i) for i in msgbin]))
                    if self._check_msg(msghex):
                        messages.append([msghex, time.time()])
                    if self.debug:
                        self._debug_msg(msghex)

-            elif i > buffer_length - 500:
-                # save some for next process
-                break
+            # elif i > buffer_length - 500:
+            #     # save some for next process
+            #     break
            else:
                i += 1

-        # keep reminder of buffer for next iteration
+        # reset the buffer
        self.signal_buffer = self.signal_buffer[i:]
+
        return messages

    def _check_preamble(self, pulses):
@@ -122,10 +144,8 @@ class RtlReader(object):
            pass

    def _read_callback(self, data, rtlsdr_obj):
-        # scaling signal (imporatant)
        amp = np.absolute(data)
-        amp_norm = np.interp(amp, (amp.min(), amp.max()), (0, 1))
-        self.signal_buffer.extend(amp_norm.tolist())
+        self.signal_buffer.extend(amp.tolist())

        if len(self.signal_buffer) >= buffer_size:
            messages = self._process_buffer()
@@ -138,18 +158,24 @@ class RtlReader(object):
            pass

    def stop(self, *args, **kwargs):
-        self.sdr.cancel_read_async()
+        self.sdr.close()

-    def run(self, raw_pipe_in=None, stop_flag=None):
+    def run(self, raw_pipe_in=None, stop_flag=None, exception_queue=None):
        self.raw_pipe_in = raw_pipe_in
        self.stop_flag = stop_flag
-        self.sdr.read_samples_async(self._read_callback, read_size)

-        # count = 1
-        # while count < 1000:
-        #     count += 1
-        #     data = self.sdr.read_samples(read_size)
-        #     self._read_callback(data, None)
+        try:
+            # raise RuntimeError("test exception")
+
+            while True:
+                data = self.sdr.read_samples(read_size)
+                self._read_callback(data, None)
+
+        except Exception as e:
+            tb = traceback.format_exc()
+            if exception_queue is not None:
+                exception_queue.put(tb)
+            raise e


 if __name__ == "__main__":
--- a/pyModeS/extra/tcpclient.py
+++ b/pyModeS/extra/tcpclient.py
@@ -1,6 +1,5 @@
 """Stream beast raw data from a TCP server, convert to mode-s messages."""

-from __future__ import print_function, division
 import os
 import sys
 import time
@@ -170,7 +169,7 @@ class TcpClient(object):
              Start character '$'

            MS field - Payload
-            Postion 1 through 14:
+            Position 1 through 14:
              14 bytes = 112 bits
              Mode-S payload
              In case of DF types that only carry 7 bytes of information
@@ -254,7 +253,7 @@ class TcpClient(object):
        for msg, t in messages:
            print("%15.9f %s" % (t, msg))

-    def run(self, raw_pipe_in=None, stop_flag=None):
+    def run(self, raw_pipe_in=None, stop_flag=None, exception_queue=None):
        self.raw_pipe_in = raw_pipe_in
        self.stop_flag = stop_flag
        self.connect()
@@ -269,11 +268,6 @@ class TcpClient(object):
                self.buffer.extend(received)
                # print(''.join(x.encode('hex') for x in self.buffer))

-                # process self.buffer when it is longer enough
-                # if len(self.buffer) < 2048:
-                #     continue
-                # -- Removed!! Cause delay in low data rate scenario --
-
                if self.datatype == "beast":
                    messages = self.read_beast_buffer()
                elif self.datatype == "raw":
@@ -286,22 +280,12 @@ class TcpClient(object):
                else:
                    self.handle_messages(messages)

-            except Exception as e:
-                # Provides the user an option to supply the environment
-                # variable PYMODES_DEBUG to halt the execution
-                # for debugging purposes
-                debug_intent = os.environ.get("PYMODES_DEBUG", "false")
-                if debug_intent.lower() == "true":
-                    traceback.print_exc()
-                    sys.exit()
-                else:
-                    print("Unexpected Error:", e)
+                # raise RuntimeError("test exception")

-                try:
-                    sock = self.connect()
-                    time.sleep(1)
-                except Exception as e:
-                    print("Unexpected Error:", e)
+            except Exception as e:
+                tb = traceback.format_exc()
+                exception_queue.put(tb)
+                raise e


 if __name__ == "__main__":
--- a/pyModeS/streamer/decode.py
+++ b/pyModeS/streamer/decode.py
@@ -1,4 +1,3 @@
-from __future__ import absolute_import, print_function, division
 import os
 import time
 import datetime
@@ -27,7 +26,7 @@ class Decode:
            self.dumpto = None

    def process_raw(self, adsb_ts, adsb_msg, commb_ts, commb_msg, tnow=None):
-        """process a chunk of adsb and commb messages recieved in the same
+        """process a chunk of adsb and commb messages received in the same
        time period.
        """
        if tnow is None:
@@ -259,26 +258,31 @@ class Decode:
        return

    def get_aircraft(self):
-        """all aircraft that are stored in memeory"""
+        """all aircraft that are stored in memory"""
        acs = self.acs
        return acs

-    def run(self, raw_pipe_out, ac_pipe_in):
+    def run(self, raw_pipe_out, ac_pipe_in, exception_queue):
        local_buffer = []
        while True:
-            while raw_pipe_out.poll():
-                data = raw_pipe_out.recv()
-                local_buffer.append(data)
+            try:
+                while raw_pipe_out.poll():
+                    data = raw_pipe_out.recv()
+                    local_buffer.append(data)

-            for data in local_buffer:
-                self.process_raw(
-                    data["adsb_ts"],
-                    data["adsb_msg"],
-                    data["commb_ts"],
-                    data["commb_msg"],
-                )
-            local_buffer = []
+                for data in local_buffer:
+                    self.process_raw(
+                        data["adsb_ts"],
+                        data["adsb_msg"],
+                        data["commb_ts"],
+                        data["commb_msg"],
+                    )
+                local_buffer = []

-            acs = self.get_aircraft()
-            ac_pipe_in.send(acs)
-            time.sleep(0.001)
+                acs = self.get_aircraft()
+                ac_pipe_in.send(acs)
+                time.sleep(0.001)
+
+            except Exception as e:
+                tb = traceback.format_exc()
+                exception_queue.put((e, tb))
--- a/pyModeS/streamer/modeslive
+++ b/pyModeS/streamer/modeslive
@@ -1,8 +1,8 @@
 #!/usr/bin/env python

-from __future__ import print_function, division
 import os
 import sys
+import time
 import argparse
 import curses
 import signal
@@ -15,7 +15,6 @@ from pyModeS.streamer.source import NetSource, RtlSdrSource
 # redirect all stdout to null, avoiding messing up with the screen
 sys.stdout = open(os.devnull, "w")

-
 support_rawtypes = ["raw", "beast", "skysense"]

 parser = argparse.ArgumentParser()
@@ -71,7 +70,7 @@ elif SOURCE == "net":
    else:
        SERVER, PORT, DATATYPE = args.connect
        if DATATYPE not in support_rawtypes:
-            print("Data type not supported, avaiable ones are %s" % support_rawtypes)
+            print("Data type not supported, available ones are %s" % support_rawtypes)

 else:
    print('Source must be "rtlsdr" or "net".')
@@ -87,13 +86,9 @@ if DUMPTO is not None:
        sys.exit(1)


-# raw_event = multiprocessing.Event()
-# ac_event = multiprocessing.Event()
-# raw_queue = multiprocessing.Queue()
-# ac_queue = multiprocessing.Queue()
-
 raw_pipe_in, raw_pipe_out = multiprocessing.Pipe()
 ac_pipe_in, ac_pipe_out = multiprocessing.Pipe()
+exception_queue = multiprocessing.Queue()
 stop_flag = multiprocessing.Value("b", False)

 if SOURCE == "net":
@@ -102,29 +97,38 @@ elif SOURCE == "rtlsdr":
    source = RtlSdrSource()


-recv_process = multiprocessing.Process(target=source.run, args=(raw_pipe_in, stop_flag))
+recv_process = multiprocessing.Process(
+    target=source.run, args=(raw_pipe_in, stop_flag, exception_queue)
+)


 decode = Decode(latlon=LATLON, dumpto=DUMPTO)
 decode_process = multiprocessing.Process(
-    target=decode.run, args=(raw_pipe_out, ac_pipe_in)
+    target=decode.run, args=(raw_pipe_out, ac_pipe_in, exception_queue)
 )

 screen = Screen(uncertainty=UNCERTAINTY)
-screen_process = multiprocessing.Process(target=screen.run, args=(ac_pipe_out,))
+screen_process = multiprocessing.Process(
+    target=screen.run, args=(ac_pipe_out, exception_queue)
+)


-def closeall(signal, frame):
-    print("KeyboardInterrupt (ID: {}). Cleaning up...".format(signal))
+def shutdown():
    stop_flag.value = True
    curses.endwin()
+    sys.stdout = sys.__stdout__
    recv_process.terminate()
    decode_process.terminate()
    screen_process.terminate()
    recv_process.join()
    decode_process.join()
    screen_process.join()
-    exit(0)
+
+
+def closeall(signal, frame):
+    print("KeyboardInterrupt (ID: {}). Cleaning up...".format(signal))
+    shutdown()
+    sys.exit(0)


 signal.signal(signal.SIGINT, closeall)
@@ -132,3 +136,19 @@ signal.signal(signal.SIGINT, closeall)
 recv_process.start()
 decode_process.start()
 screen_process.start()
+
+
+while True:
+    if (
+        (not recv_process.is_alive())
+        or (not decode_process.is_alive())
+        or (not screen_process.is_alive())
+    ):
+        shutdown()
+        while not exception_queue.empty():
+            trackback = exception_queue.get()
+            print(trackback)
+
+        sys.exit(1)
+
+    time.sleep(0.01)
--- a/pyModeS/streamer/screen.py
+++ b/pyModeS/streamer/screen.py
@@ -1,8 +1,8 @@
-from __future__ import print_function, division
 import curses
 import numpy as np
 import time
 import threading
+import traceback

 COLUMNS = [
    ("call", 10),
@@ -187,24 +187,32 @@ class Screen(object):
                self.screen.refresh()
                self.draw_frame()

-    def run(self, ac_pipe_out):
+    def run(self, ac_pipe_out, exception_queue):
        local_buffer = []
        key_thread = threading.Thread(target=self.kye_handling)
+        key_thread.daemon = True
        key_thread.start()

        while True:
-            while ac_pipe_out.poll():
-                acs = ac_pipe_out.recv()
-                local_buffer.append(acs)
-
-            for acs in local_buffer:
-                self.update_ac(acs)
-
-            local_buffer = []
-
            try:
+                # raise RuntimeError("test exception")
+
+                while ac_pipe_out.poll():
+                    acs = ac_pipe_out.recv()
+                    local_buffer.append(acs)
+
+                for acs in local_buffer:
+                    self.update_ac(acs)
+
+                local_buffer = []
+
                self.update()
-            except:
+            except curses.error:
                pass
+            except Exception as e:
+                tb = traceback.format_exc()
+                exception_queue.put(tb)
+                time.sleep(0.1)
+                raise e

            time.sleep(0.001)
--- a/setup.py
+++ b/setup.py
@@ -4,7 +4,7 @@ See:
 https://packaging.python.org/en/latest/distributing.html
 https://github.com/pypa/sampleproject

-Steps for deploying a new verison:
+Steps for deploying a new version:
 1. Increase the version number
 2. remove the old deployment under [dist] and [build] folder
 3. run: python setup.py sdist
@@ -15,6 +15,13 @@ Steps for deploying a new verison:
 # Always prefer setuptools over distutils
 from setuptools import setup, find_packages

+# Compile some parts
+from setuptools.extension import Extension
+from Cython.Build import cythonize
+
+extensions = [Extension("pyModeS.c_common", ["pyModeS/c_common.pyx"])]
+
+
 # To use a consistent encoding
 from codecs import open
 from os import path
@@ -30,7 +37,7 @@ setup(
    # Versions should comply with PEP440.  For a discussion on single-sourcing
    # the version across setup.py and the project code, see
    # https://packaging.python.org/en/latest/single_source_version.html
-    version="2.4",
+    version="2.5",
    description="Python Mode-S and ADS-B Decoder",
    long_description=long_description,
    # The project's main homepage.
@@ -49,21 +56,17 @@ setup(
        "Development Status :: 4 - Beta",
        # Indicate who your project is intended for
        "Intended Audience :: Developers",
-        "Topic :: Software Development :: Build Tools",
+        "Topic :: Software Development :: Libraries",
        # Pick your license as you wish (should match "license" above)
        "License :: OSI Approved :: GNU General Public License v3 (GPLv3)",
        # Specify the Python versions you support here. In particular, ensure
        # that you indicate whether you support Python 2, Python 3 or both.
-        "Programming Language :: Python :: 2",
-        "Programming Language :: Python :: 2.7",
+        # "Programming Language :: Python :: 2",
        "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.3",
-        "Programming Language :: Python :: 3.4",
-        "Programming Language :: Python :: 3.5",
-        "Programming Language :: Python :: 3.6",
    ],
+    ext_modules=cythonize(extensions),
    # What does your project relate to?
-    keywords="Mode-S ADS-B EHS decoding",
+    keywords="Mode-S ADS-B EHS ELS Comm-B",
    # You can just specify the packages manually here if your project is
    # simple. Or you can use find_packages().
    packages=find_packages(exclude=["contrib", "docs", "tests"]),
@@ -74,7 +77,7 @@ setup(
    # your project is installed. For an analysis of "install_requires" vs pip's
    # requirements files see:
    # https://packaging.python.org/en/latest/requirements.html
-    install_requires=["numpy", "argparse", "pyzmq", "pyrtlsdr"],
+    install_requires=["numpy", "pyzmq", "pyrtlsdr"],
    # List additional groups of dependencies here (e.g. development
    # dependencies). You can install these using the following syntax,
    # for example:
--- a/tests/benchmark.py
+++ b/tests/benchmark.py
@@ -0,0 +1,130 @@
+import sys
+import time
+import pandas as pd
+from tqdm import tqdm
+from pyModeS.decoder import adsb
+
+fin = sys.argv[1]
+
+df = pd.read_csv(fin, names=["ts", "df", "icao", "msg"])
+df_adsb = df[df["df"] == 17].copy()
+
+total = df_adsb.shape[0]
+
+
+def native():
+
+    from pyModeS.decoder import common
+
+    # airborne position
+    m_air_0 = None
+    m_air_1 = None
+
+    # surface position
+    m_surf_0 = None
+    m_surf_1 = None
+
+    for i, r in tqdm(df_adsb.iterrows(), total=total):
+        ts = r.ts
+        m = r.msg
+
+        downlink_format = common.df(m)
+        crc = common.crc(m)
+        icao = adsb.icao(m)
+        tc = adsb.typecode(m)
+
+        if 1 <= tc <= 4:
+            category = adsb.category(m)
+            callsign = adsb.callsign(m)
+        if tc == 19:
+            velocity = adsb.velocity(m)
+
+        if 5 <= tc <= 8:
+            if adsb.oe_flag(m):
+                m_surf_1 = m
+                t1 = ts
+            else:
+                m_surf_0 = m
+                t0 = ts
+
+            if m_surf_0 and m_surf_1:
+                position = adsb.surface_position(
+                    m_surf_0, m_surf_1, t0, t1, 50.01, 4.35
+                )
+                altitude = adsb.altitude(m)
+
+        if 9 <= tc <= 18:
+            if adsb.oe_flag(m):
+                m_air_1 = m
+                t1 = ts
+            else:
+                m_air_0 = m
+                t0 = ts
+
+            if m_air_0 and m_air_1:
+                position = adsb.position(m_air_0, m_air_1, t0, t1)
+                altitude = adsb.altitude(m)
+
+
+def cython():
+
+    from pyModeS.decoder import c_common as common
+
+    # airborne position
+    m_air_0 = None
+    m_air_1 = None
+
+    # surface position
+    m_surf_0 = None
+    m_surf_1 = None
+
+    for i, r in tqdm(df_adsb.iterrows(), total=total):
+        ts = r.ts
+        m = r.msg
+
+        downlink_format = common.df(m)
+        crc = common.crc(m)
+        icao = adsb.icao(m)
+        tc = adsb.typecode(m)
+
+        if 1 <= tc <= 4:
+            category = adsb.category(m)
+            callsign = adsb.callsign(m)
+        if tc == 19:
+            velocity = adsb.velocity(m)
+
+        if 5 <= tc <= 8:
+            if adsb.oe_flag(m):
+                m_surf_1 = m
+                t1 = ts
+            else:
+                m_surf_0 = m
+                t0 = ts
+
+            if m_surf_0 and m_surf_1:
+                position = adsb.surface_position(
+                    m_surf_0, m_surf_1, t0, t1, 50.01, 4.35
+                )
+                altitude = adsb.altitude(m)
+
+        if 9 <= tc <= 18:
+            if adsb.oe_flag(m):
+                m_air_1 = m
+                t1 = ts
+            else:
+                m_air_0 = m
+                t0 = ts
+
+            if m_air_0 and m_air_1:
+                position = adsb.position(m_air_0, m_air_1, t0, t1)
+                altitude = adsb.altitude(m)
+
+
+if __name__ == "__main__":
+    t1 = time.time()
+    native()
+    dt1 = time.time() - t1
+
+    t2 = time.time()
+    cython()
+    dt2 = time.time() - t2
--- a/tests/sample_run_adsb.py
+++ b/tests/sample_run_adsb.py
@@ -1,44 +1,46 @@
-from __future__ import print_function
-from pyModeS import adsb, ehs
+import sys
+import time
+import csv
+
+if len(sys.argv) > 1 and sys.argv[1] == "cython":
+    from pyModeS.c_decoder import adsb
+else:
+    from pyModeS.decoder import adsb
+
+print("===== Decode ADS-B sample data=====")
+
+f = open("tests/data/sample_data_adsb.csv", "rt")
+
+msg0 = None
+msg1 = None
+
+tstart = time.time()
+for i, r in enumerate(csv.reader(f)):
+
+    ts = int(r[0])
+    m = r[1].encode()
+
+    icao = adsb.icao(m)
+    tc = adsb.typecode(m)
+
+    if 1 <= tc <= 4:
+        print(ts, m, icao, tc, adsb.category(m), adsb.callsign(m))
+    if tc == 19:
+        print(ts, m, icao, tc, adsb.velocity(m))
+    if 5 <= tc <= 18:
+        if adsb.oe_flag(m):
+            msg1 = m
+            t1 = ts
+        else:
+            msg0 = m
+            t0 = ts
+
+        if msg0 and msg1:
+            pos = adsb.position(msg0, msg1, t0, t1)
+            alt = adsb.altitude(m)
+            print(ts, m, icao, tc, pos, alt)


-# === Decode sample data file ===
+dt = time.time() - tstart

-
-def adsb_decode_all(n=None):
-    print("===== Decode ADS-B sample data=====")
-    import csv
-
-    f = open("tests/data/sample_data_adsb.csv", "rt")
-
-    msg0 = None
-    msg1 = None
-
-    for i, r in enumerate(csv.reader(f)):
-        if n and i > n:
-            break
-
-        ts = r[0]
-        m = r[1]
-        icao = adsb.icao(m)
-        tc = adsb.typecode(m)
-        if 1 <= tc <= 4:
-            print(ts, m, icao, tc, adsb.category(m), adsb.callsign(m))
-        if tc == 19:
-            print(ts, m, icao, tc, adsb.velocity(m))
-        if 5 <= tc <= 18:
-            if adsb.oe_flag(m):
-                msg1 = m
-                t1 = ts
-            else:
-                msg0 = m
-                t0 = ts
-
-            if msg0 and msg1:
-                pos = adsb.position(msg0, msg1, t0, t1)
-                alt = adsb.altitude(m)
-                print(ts, m, icao, tc, pos, alt)
-
-
-if __name__ == "__main__":
-    adsb_decode_all(n=100)
+print("Execution time: {} seconds".format(dt))
--- a/tests/sample_run_commb.py
+++ b/tests/sample_run_commb.py
@@ -1,4 +1,3 @@
-from __future__ import print_function
 from pyModeS import commb, common, bds

 # === Decode sample data file ===
--- a/tests/test_c_common.py
+++ b/tests/test_c_common.py
@@ -0,0 +1,58 @@
+try:
+    from pyModeS.decoder import c_common as common
+
+    def test_conversions():
+        assert common.hex2bin("6E406B") == "011011100100000001101011"
+
+    def test_crc_decode():
+
+        assert common.crc("8D406B902015A678D4D220AA4BDA") == 0
+        assert common.crc("8d8960ed58bf053cf11bc5932b7d") == 0
+        assert common.crc("8d45cab390c39509496ca9a32912") == 0
+        assert common.crc("8d74802958c904e6ef4ba0184d5c") == 0
+        assert common.crc("8d4400cd9b0000b4f87000e71a10") == 0
+        assert common.crc("8d4065de58a1054a7ef0218e226a") == 0
+
+        assert common.crc("c80b2dca34aa21dd821a04cb64d4") == 10719924
+        assert common.crc("a800089d8094e33a6004e4b8a522") == 4805588
+        assert common.crc("a8000614a50b6d32bed000bbe0ed") == 5659991
+        assert common.crc("a0000410bc900010a40000f5f477") == 11727682
+        assert common.crc("8d4ca251204994b1c36e60a5343d") == 16
+        assert common.crc("b0001718c65632b0a82040715b65") == 353333
+
+    def test_crc_encode():
+        parity = common.crc("8D406B902015A678D4D220AA4BDA", encode=True)
+        assert parity == 11160538
+
+    def test_icao():
+        assert common.icao("8D406B902015A678D4D220AA4BDA") == "406B90"
+        assert common.icao("A0001839CA3800315800007448D9") == "400940"
+        assert common.icao("A000139381951536E024D4CCF6B5") == "3C4DD2"
+        assert common.icao("A000029CFFBAA11E2004727281F1") == "4243D0"
+
+    def test_modes_altcode():
+        assert common.altcode("A02014B400000000000000F9D514") == 32300
+
+    def test_modes_idcode():
+        assert common.idcode("A800292DFFBBA9383FFCEB903D01") == "1346"
+
+    def test_graycode_to_altitude():
+        assert common.gray2alt("00000000010") == -1000
+        assert common.gray2alt("00000001010") == -500
+        assert common.gray2alt("00000011011") == -100
+        assert common.gray2alt("00000011010") == 0
+        assert common.gray2alt("00000011110") == 100
+        assert common.gray2alt("00000010011") == 600
+        assert common.gray2alt("00000110010") == 1000
+        assert common.gray2alt("00001001001") == 5800
+        assert common.gray2alt("00011100100") == 10300
+        assert common.gray2alt("01100011010") == 32000
+        assert common.gray2alt("01110000100") == 46300
+        assert common.gray2alt("01010101100") == 50200
+        assert common.gray2alt("11011110100") == 73200
+        assert common.gray2alt("10000000011") == 126600
+        assert common.gray2alt("10000000001") == 126700
+
+
+except:
+    pass
--- a/tests/test_common.py
+++ b/tests/test_common.py
@@ -3,8 +3,6 @@ from pyModeS import common

 def test_conversions():
    assert common.hex2bin("6E406B") == "011011100100000001101011"
-    assert common.bin2hex("011011100100000001101011") == "6E406B"
-    assert common.int2hex(11160538) == "AA4BDA"


 def test_crc_decode():
@@ -28,7 +26,7 @@ def test_crc_decode():

 def test_crc_encode():
    parity = common.crc("8D406B902015A678D4D220AA4BDA", encode=True)
-    assert common.int2hex(parity) == "AA4BDA"
+    assert parity == 11160538


 def test_icao():
--- a/tests/test_encoder.py
+++ b/tests/test_encoder.py
@@ -0,0 +1,23 @@
+from pyModeS import encoder
+
+
+def test_identification():
+    msg = encoder.encode_adsb(
+        icao="406B90", typecode=4, capability=5, category=0, callsign="EZY85MH"
+    )
+    assert msg == "8D406B902015A678D4D220AA4BDA"
+
+
+def test_speed():
+    msg = encoder.encode_adsb(
+        icao="485020",
+        typecode=19,
+        capability=5,
+        speed_type="gs",
+        speed=159,
+        angle=182.88,
+        vertical_rate=-832,
+        vertical_rate_source="gnss",
+        gnss_baro_alt_diff=550,
+    )
+    assert msg == "8D485020994409940838175B284F"
--- a/tox.ini
+++ b/tox.ini
@@ -1,11 +0,0 @@
-[tox]
-toxworkdir = /tmp/tox
-envlist = py2,py3
-
-[testenv]
-deps =
-  pytest
-  numpy
-  pyzmq
-  pyrtlsdr
-commands = py.test
Author	SHA1	Message	Date
Junzi Sun	59d21de725	Merge branch 'master' into adsb_encoder	2020-05-04 01:53:27 +02:00
Junzi Sun	560b737739	update api link	2020-05-04 01:51:33 +02:00
Junzi Sun	d50f05d00d	Merge branch 'master' of github.com:junzis/pyModeS	2020-05-04 01:09:40 +02:00
Junzi Sun	11a560dbb5	update API doc	2020-05-04 01:07:02 +02:00
Junzi Sun	b51facbdc6	update docstring	2020-05-04 00:56:36 +02:00
Junzi Sun	d77d1f7f6b	update docstring	2020-05-04 00:11:29 +02:00
Junzi Sun	aff0f75de2	BDS08 and BDS09 encoders	2020-05-03 23:29:10 +02:00
Junzi Sun	5286355bf6	move common package to root level	2020-05-03 23:27:17 +02:00
Junzi Sun	fe9e033a64	update comments	2020-05-03 20:13:22 +02:00
Junzi Sun	57307109e6	remove python 2 imports	2020-05-02 19:32:54 +02:00
Junzi Sun	6571fe6fc0	Update README.rst	2020-04-04 20:48:23 +02:00
Junzi Sun	aa64d4e7a9	update README	2020-04-04 20:44:46 +02:00
wrobell	db57d7419f	Improve doc for surface position decoding	2020-03-11 22:08:04 +01:00
Junzi Sun	ed18352c0c	update NL() function in CPR decoding	2020-03-03 12:39:39 +01:00
Junzi Sun	a75d6fd050	install c module	2020-02-26 00:55:25 +01:00
Junzi Sun	0ff628bb8e	update imports	2020-02-26 00:54:49 +01:00
Junzi Sun	ea7653ef79	update test	2020-02-26 00:25:11 +01:00
Junzi Sun	2046b1de07	speedup (#59 ) * remove unused functions * cythonize common * add bds05 * separate cleanly cython and python, bds05, bds06, modulo issues * bds08 * bds09 * optimisations in bds09 * "make" things easier * clean up useless stuff * add make options * fix hidden altitude() call * minor updates to C code * update tests * update benchmark * consolidation * update clean script * reduce complexity and change default type to str Co-authored-by: Xavier Olive <1360812+xoolive@users.noreply.github.com>	2020-02-26 00:16:48 +01:00
Junzi Sun	768b80df8e	improve modeslive	2020-02-25 21:30:42 +01:00
Junzi Sun	e52d43f963	update rtlsdr reader	2020-02-14 17:53:56 +01:00
Junzi Sun	b60b31d4fb	release 2.5	2020-02-14 10:47:34 +01:00
Flyer350	cb67c63326	Create uplink.py (#55 ) First basic functionality for uplink messages - UF and ICAO address.	2019-12-31 11:16:55 +01:00
Xavier Olive	bddaf9aec6	compatibility with bytes (#57 )	2019-12-31 11:15:25 +01:00
Junzi Sun	00fc1475ff	Merge pull request #53 from dforsi/fix-typos Fix typos	2019-11-19 11:17:41 +01:00
Daniele Forsi	489c405de0	Fix typos Fixed with the command: codespell --write-changes --ignore-words-list hve,vas codespell is available at https://github.com/lucasdemarchi/codespell	2019-10-31 13:38:46 +01:00
Junzi Sun	ec2721cfdc	Merge pull request #52 from Flyer350/patch-1 Update README.rst	2019-10-30 20:42:19 +01:00
Flyer350	2f13524a7c	Update README.rst fixed typecodes for position messages	2019-10-30 15:54:37 +01:00
Junzi Sun	fb24d4f25c	minor speed improvements	2019-10-16 16:24:38 +02:00
Junzi Sun	9ad535dc93	update package info	2019-09-30 23:50:07 +02:00
Junzi Sun	9a89766766	update installation guide	2019-09-24 21:36:48 +02:00
				`@@ -1 +0,0 @@`
				`from __future__ import absolute_import, print_function, division`