release version 1.2.2

update identification function for BDS44

README.rst

@@ -1,21 +1,30 @@
-A Python Mode-S Decoder
-=======================
+The Python Mode-S Decoder
+=========================
 
-Python library for Mode-S message decoding. Two separate methods are
-implemented to decode the following messages:
+Python library for Mode-S message decoding. Support Downlink Formats (DF) are:
 
 -  Automatic Dependent Surveillance - Broadcast (ADS-B) (DF17)
 
-   -  aircraft information that contains: ICAO address, position,
-      altitude, velocity (ground speed), callsign, etc.
+   -  aircraft information that contains: ICAO address, position, altitude, velocity (ground speed), callsign, etc.
 
--  Mode-S Enhanced Surveillance (EHS) (DF20 and DF21)
+-  Mode-S Elementary Surveillance (ELS) (DF4 and DF5).
 
-   -  additional information in response to SSR interrogation, such as:
-      true airspeed, indicated airspeed, mach number, track angle,
-      heading, roll angle, etc.
+   - DF4: Altitude
+   - DF5: Squawk code
 
-A detailed manual on Mode-S decoding is published by the author, at:
+-  Mode-S Enhanced Surveillance (EHS) (DF20 and DF21). Additional information in response to SSR interrogation, such as: true airspeed, indicated airspeed, mach number, wind, temperature, etc.
+
+   - DF20: Altitude
+   - DF21: Squawk code
+   - BDS 2,0   Aircraft identification
+   - BDS 2,1   Aircraft and airline registration markings
+   - BDS 4,0   Selected vertical intention
+   - BDS 4,4   Meteorological routine air report
+   - BDS 5,0   Track and turn report
+   - BDS 5,3   Air-referenced state vector
+   - BDS 6,0   Heading and speed report
+
+Detailed manual on Mode-S decoding is published by the author, at:
 http://adsb-decode-guide.readthedocs.io
 
 
@@ -27,92 +36,147 @@ https://github.com/junzis/pyModeS
 API documentation at:
 http://pymodes.readthedocs.io
 
+
 Install
 -------
 
-Checkout source code, or install using pip:
+The easiest installation is to use pip:
 
 ::
 
-    pip install pyModeS
+  pip install pyModeS
 
-Usage
------
+To install latest devlopment version from the GitHub:
+
+::
+
+  pip install git+https://github.com/junzis/pyModeS
+
+
+Use the library
+---------------
 
 .. code:: python
 
-    import pyModeS as pms
+  import pyModeS as pms
 
 
-Common function for Mode-S message:
+Common functions:
+*****************
 
 .. code:: python
 
-    pms.df(msg)                 # Downlink Format
-    pms.crc(msg, encode=False)  # Perform CRC or generate parity bit
+  pms.df(msg)                 # Downlink Format
+  pms.crc(msg, encode=False)  # Perform CRC or generate parity bit
 
-    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.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
 
 
 Core functions for ADS-B decoding:
+**********************************
 
 .. code:: python
 
-    pms.adsb.icao(msg)
-    pms.adsb.callsign(msg)
+  pms.adsb.icao(msg)
+  pms.adsb.typecode(msg)
 
-    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)
+  # typecode 1-4
+  pms.adsb.callsign(msg)
 
-    pms.adsb.position_with_ref(msg, lat_ref, lon_ref)
-    pms.adsb.airborne_position_with_ref(msg, lat_ref, lon_ref)
-    pms.adsb.surface_position_with_ref(msg, lat_ref, lon_ref)
+  # typecode 5-8 (surface) and 9-18 (airborne)
+  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)
 
-    pms.adsb.altitude(msg)
-    pms.adsb.velocity(msg)
-    pms.adsb.speed_heading(msg)
+  pms.adsb.position_with_ref(msg, lat_ref, lon_ref)
+  pms.adsb.airborne_position_with_ref(msg, lat_ref, lon_ref)
+  pms.adsb.surface_position_with_ref(msg, lat_ref, lon_ref)
 
-**Hint: When you have a fix position of the aircraft, it is convenient to
+  pms.adsb.altitude(msg)
+
+  # typecode: 19
+  pms.adsb.velocity(msg)          # handles both surface & airborne messages
+  pms.adsb.speed_heading(msg)     # handles both surface & airborne messages
+  pms.adsb.surface_velocity(msg)
+  pms.adsb.airborne_velocity(msg)
+
+
+Note: When you have a fix position of the aircraft, it is convenient to
 use `position_with_ref()` method to decode with only one position message
 (either odd or even). This works with both airborne and surface position
 messages. But the reference position shall be with in 180NM (airborne)
-or 45NM (surface) of the true position.**
+or 45NM (surface) of the true position.
 
-Core functions for EHS decoding:
+Core functions for ELS decoding:
+********************************
 
 .. code:: python
 
-    pms.ehs.icao(msg)       # ICAO address
-    pms.ehs.BDS(msg)        # Comm-B Data Selector Version
+  pms.els.icao(msg)       # ICAO address
+  pms.els.df4alt(msg)     # Altitude from any DF4 message
+  pms.ehs.df5id(msg)     # Squawk code from any DF5 message
 
-    # for BDS version 2,0
-    pms.ehs.callsign(msg)   # Aircraft callsign
 
-    # for BDS version 4,0
-    pms.ehs.alt_mcp(msg)    # MCP/FCU selected altitude (ft)
-    pms.ehs.alt_fms(msg)    # FMS selected altitude (ft)
-    pms.ehs.alt_pbaro(msg)  # Barometric pressure (mb)
+Core functions for EHS decoding:
+********************************
 
-    # for BDS version 5,0
-    pms.ehs.roll(msg)       # roll angle (deg)
-    pms.ehs.track(msg)      # track angle (deg)
-    pms.ehs.gs(msg)         # ground speed (kt)
-    pms.ehs.rtrack(msg)     # track angle rate (deg/sec)
-    pms.ehs.tas(msg)        # true airspeed (kt)
+.. code:: python
 
-    # for BDS version 6,0
-    pms.ehs.heading(msg)    # heading (deg)
-    pms.ehs.ias(msg)        # indicated airspeed (kt)
-    pms.ehs.mach(msg)       # MACH number
-    pms.ehs.baro_vr(msg)    # barometric altitude rate (ft/min)
-    pms.ehs.ins_vr(msg)     # inertial vertical speed (ft/min)
+  pms.ehs.icao(msg)       # ICAO address
+  pms.ehs.df20alt(msg)    # Altitude from any DF20 message
+  pms.ehs.df21id(msg)     # Squawk code from any DF21 message
+
+  pms.ehs.BDS(msg)        # Comm-B Data Selector Version
+
+  # for BDS version 2,0
+  pms.ehs.isBDS20(msg)    # Check if message is BDS 2,0
+  pms.ehs.callsign(msg)   # Aircraft callsign
+
+  # for BDS version 4,0
+  pms.ehs.isBDS40(msg)    # Check if message is BDS 4,0
+  pms.ehs.alt40mcp(msg)   # MCP/FCU selected altitude (ft)
+  pms.ehs.alt40fms(msg)   # FMS selected altitude (ft)
+  pms.ehs.p40baro(msg)    # Barometric pressure (mb)
+
+  # for BDS version 4,4
+  pms.ehs.isBDS44(msg, rev=False) # Check if message is BDS 4,4
+  pms.ehs.wind44(msg, rev=False)  # wind speed (kt) and heading (deg)
+  pms.ehs.temp44(msg, rev=False)  # temperature (C)
+  pms.ehs.p44(msg, rev=False)     # pressure (hPa)
+  pms.ehs.hum44(msg, rev=False)   # humidity (%)
+
+  # for BDS version 5,0
+  pms.ehs.isBDS50(msg)    # Check if message is BDS 5,0
+  pms.ehs.roll50(msg)     # roll angle (deg)
+  pms.ehs.trk50(msg)      # track angle (deg)
+  pms.ehs.gs50(msg)       # ground speed (kt)
+  pms.ehs.rtrk50(msg)     # track angle rate (deg/sec)
+  pms.ehs.tas50(msg)      # true airspeed (kt)
+
+  # for BDS version 5,3
+  pms.ehs.isBDS53(msg)    # Check if message is BDS 5,3
+  pms.ehs.hdg53(msg)      # magnetic heading (deg)
+  pms.ehs.ias53(msg)      # indicated airspeed (kt)
+  pms.ehs.mach53(msg)     # MACH number
+  pms.ehs.tas53(msg)      # true airspeed (kt)
+  pms.ehs.vr53(msg)       # vertical rate (fpm)
+
+  # for BDS version 6,0
+  pms.ehs.isBDS60(msg)    # Check if message is BDS 6,0
+  pms.ehs.hdg60(msg)      # heading (deg)
+  pms.ehs.ias60(msg)      # indicated airspeed (kt)
+  pms.ehs.mach60(msg)     # MACH number
+  pms.ehs.vr60baro(msg)   # barometric altitude rate (ft/min)
+  pms.ehs.vr60ins(msg)    # inertial vertical speed (ft/min)
 
 Developement
 ------------
-To run tests, run the following commands:
-```
-$ tox
-```
+To perform unit tests. First install ``tox`` through pip, Then, run the following commands:
+
+.. code:: bash
+
+  $ tox

doc/requirements.txt

@@ -1 +1 @@
-pyModeS==1.0.5
+pyModeS==1.1.0

pyModeS/__init__.py

@@ -3,3 +3,4 @@ from __future__ import absolute_import, print_function, division
 from .util import *
 from . import adsb
 from . import ehs
+from . import els

pyModeS/adsb.py

@@ -17,6 +17,7 @@
 A python package for decoding ABS-D messages.
 """
 
+from __future__ import absolute_import, print_function, division
 import math
 from . import util
 
@@ -265,19 +266,18 @@ def position_with_ref(msg, lat_ref, lon_ref):
     of the true position.
 
     Args:
-        msg0 (string): even message (28 bytes hexadecimal string)
-        msg1 (string): odd message (28 bytes hexadecimal string)
-        t0 (int): timestamps for the even message
-        t1 (int): timestamps for the odd message
+        msg (string): even message (28 bytes hexadecimal string)
+        lat_ref: previous known latitude
+        lon_ref: previous known longitude
 
     Returns:
         (float, float): (latitude, longitude) of the aircraft
     """
     if 5 <= typecode(msg) <= 8:
-        return airborne_position_with_ref(msg, lat_ref, lon_ref)
+        return surface_position_with_ref(msg, lat_ref, lon_ref)
 
     elif 9 <= typecode(msg) <= 18:
-        return surface_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")
@@ -427,9 +427,9 @@ def surface_position_with_ref(msg, lat_ref, lon_ref):
     ni = _cprNL(lat) - i
 
     if ni > 0:
-        d_lon = 360.0 / ni
+        d_lon = 90.0 / ni
     else:
-        d_lon = 360.0
+        d_lon = 90.0
 
     m = util.floor(lon_ref / d_lon) \
         + util.floor(0.5 + ((lon_ref % d_lon) / d_lon) - cprlon)
@@ -468,9 +468,14 @@ def altitude(msg):
     Returns:
         int: altitude in feet
     """
-    if typecode(msg) < 9 or typecode(msg) > 18:
+
+    if typecode(msg) < 5 or typecode(msg) > 18:
         raise RuntimeError("%s: Not a position message" % msg)
 
+    if typecode(msg) >=5 and typecode(msg) <=8:
+        # surface position, altitude 0
+        return 0
+
     msgbin = util.hex2bin(msg)
     q = msgbin[47]
     if q:
@@ -491,7 +496,7 @@ def nic(msg):
         int: NIC number (from 0 to 11), -1 if not applicable
     """
     if typecode(msg) < 9 or typecode(msg) > 18:
-        raise RuntimeError("%s: Not a airborne position message" % msg)
+        raise RuntimeError("%s: Not a airborne position message, expecting 8<TC<19" % msg)
 
     msgbin = util.hex2bin(msg)
     tc = typecode(msg)
@@ -534,62 +539,158 @@ def nic(msg):
 
 def velocity(msg):
     """Calculate the speed, heading, and vertical rate
+    (handles both airborne or surface message)
 
     Args:
         msg (string): 28 bytes hexadecimal message string
 
     Returns:
-        (int, float, int, string): speed (kt), heading (degree),
+        (int, float, int, string): speed (kt), ground track or heading (degree),
+            rate of climb/descend (ft/min), and speed type
+            ('GS' for ground speed, 'AS' for airspeed)
+    """
+
+    if 5 <= typecode(msg) <= 8:
+        return surface_velocity(msg)
+
+    elif typecode(msg) == 19:
+        return airborne_velocity(msg)
+
+    else:
+        raise RuntimeError("incorrect or inconsistant message types, expecting 4<TC<9 or TC=19")
+
+def speed_heading(msg):
+    """Get speed and ground track (or heading) from the velocity message
+    (handles both airborne or surface message)
+
+    Args:
+        msg (string): 28 bytes hexadecimal message string
+
+    Returns:
+        (int, float): speed (kt), ground track or heading (degree)
+    """
+    spd, trk_or_hdg, rocd, tag = velocity(msg)
+    return spd, trk_or_hdg
+
+
+def airborne_velocity(msg):
+    """Calculate the speed, track (or heading), and vertical rate
+
+    Args:
+        msg (string): 28 bytes hexadecimal message string
+
+    Returns:
+        (int, float, int, string): speed (kt), ground track or heading (degree),
             rate of climb/descend (ft/min), and speed type
             ('GS' for ground speed, 'AS' for airspeed)
     """
 
     if typecode(msg) != 19:
-        raise RuntimeError("%s: Not a airborne velocity message" % msg)
+        raise RuntimeError("%s: Not a airborne velocity message, expecting TC=19" % msg)
 
     msgbin = util.hex2bin(msg)
 
     subtype = util.bin2int(msgbin[37:40])
 
+    if util.bin2int(msgbin[46:56]) == 0 or util.bin2int(msgbin[57:67]) == 0:
+        return None
+
     if subtype in (1, 2):
-        v_ew_sign = util.bin2int(msgbin[45])
+        v_ew_sign = -1 if int(msgbin[45]) else 1
         v_ew = util.bin2int(msgbin[46:56]) - 1       # east-west velocity
 
-        v_ns_sign = util.bin2int(msgbin[56])
+        v_ns_sign = -1 if int(msgbin[56]) else 1
         v_ns = util.bin2int(msgbin[57:67]) - 1       # north-south velocity
 
-        v_we = -1*v_ew if v_ew_sign else v_ew
-        v_sn = -1*v_ns if v_ns_sign else v_ns
+
+        v_we = v_ew_sign * v_ew
+        v_sn = v_ns_sign * v_ns
 
         spd = math.sqrt(v_sn*v_sn + v_we*v_we)  # unit in kts
 
-        hdg = math.atan2(v_we, v_sn)
-        hdg = math.degrees(hdg)                 # convert to degrees
-        hdg = hdg if hdg >= 0 else hdg + 360    # no negative val
+        trk = math.atan2(v_we, v_sn)
+        trk = math.degrees(trk)                 # convert to degrees
+        trk = trk if trk >= 0 else trk + 360    # no negative val
 
         tag = 'GS'
+        trk_or_hdg = trk
 
     else:
         hdg = util.bin2int(msgbin[46:56]) / 1024.0 * 360.0
         spd = util.bin2int(msgbin[57:67])
 
         tag = 'AS'
+        trk_or_hdg = hdg
 
-    vr_sign = util.bin2int(msgbin[68])
+    vr_sign = -1 if int(msgbin[68]) else 1
     vr = (util.bin2int(msgbin[69:78]) - 1) * 64     # vertical rate, fpm
-    rocd = -1*vr if vr_sign else vr                 # rate of climb/descend
+    rocd = vr_sign * vr
 
-    return int(spd), round(hdg, 1), int(rocd), tag
+    return int(spd), round(trk_or_hdg, 1), int(rocd), tag
 
 
-def speed_heading(msg):
-    """Get speed and heading only from the velocity message
-
+def surface_velocity(msg):
+    """Decode surface velocity from from a surface position message
     Args:
         msg (string): 28 bytes hexadecimal message string
 
     Returns:
-        (int, float): speed (kt), heading (degree)
+        (int, float, int, string): speed (kt), ground track (degree),
+            rate of climb/descend (ft/min), and speed type
+            ('GS' for ground speed, 'AS' for airspeed)
     """
-    spd, hdg, rocd, tag = velocity(msg)
-    return spd, hdg
+
+    if typecode(msg) < 5 or typecode(msg) > 8:
+        raise RuntimeError("%s: Not a surface message, expecting 5<TC<8" % msg)
+
+    msgbin = util.hex2bin(msg)
+
+    # ground track
+    trk_status = int(msgbin[44])
+    if trk_status == 1:
+        trk = util.bin2int(msgbin[45:52]) * 360.0 / 128.0
+        trk = round(trk, 1)
+    else:
+        trk = None
+
+    # ground movment / speed
+    mov = util.bin2int(msgbin[37:44])
+
+    if mov == 0 or mov > 124:
+        spd = None
+    elif mov == 1:
+        spd = 0
+    elif mov == 124:
+        spd = 175
+    else:
+        movs = [2, 9, 13, 39, 94, 109, 124]
+        kts = [0.125, 1, 2, 15, 70, 100, 175]
+        i = next(m[0] for m in enumerate(movs) if m[1] > mov)
+        step = (kts[i] - kts[i-1]) * 1.0 / (movs[i]-movs[i-1])
+        spd = kts[i-1] + (mov-movs[i-1]) * step
+        spd = round(spd, 2)
+
+    return spd, trk, 0, 'GS'
+
+def altitude_diff(msg):
+    """Decode the differece between GNSS and barometric altitude
+
+    Args:
+        msg (string): 28 bytes hexadecimal message string, TC=19
+
+    Returns:
+        int: Altitude difference in ft. Negative value indicates GNSS altitude
+            below barometric altitude.
+    """
+
+    if typecode(msg) != 19:
+        raise RuntimeError("incorrect message types, expecting TC=19")
+
+    msgbin = util.hex2bin(msg)
+    sign = -1 if int(msgbin[80]) else 1
+    value = util.bin2int(msgbin[81:88])
+
+    if value == 0 or value == 127:
+        return None
+    else:
+        return sign * (value - 1) * 25    # in ft.

pyModeS/ehs.py

@@ -17,47 +17,31 @@
 A python package for decoding ModeS (DF20, DF21) messages.
 """
 
-from . import util
-from .util import crc
-
-
-def df(msg):
-    """Get the downlink format (DF) number
-
-    Args:
-        msg (String): 28 bytes hexadecimal message string
-
-    Returns:
-        int: DF number
-    """
-    return util.df(msg)
+from __future__ import absolute_import, print_function, division
+from . import util, modes_common
 
+def icao(msg):
+    return modes_common.icao(msg)
 
 def data(msg):
     """Return the data frame in the message, bytes 9 to 22"""
     return msg[8:22]
 
-
-def icao(msg):
-    """Calculate the ICAO address from an Mode-S message
-    with DF4, DF5, DF20, DF21
+def isnull(msg):
+    """check if the data bits are all zeros
 
     Args:
         msg (String): 28 bytes hexadecimal message string
 
     Returns:
-        String: ICAO address in 6 bytes hexadecimal string
+        bool: True or False
     """
+    d = util.hex2bin(data(msg))
 
-    if df(msg) not in (4, 5, 20, 21):
-        # raise RuntimeError("Message DF must be in (4, 5, 20, 21)")
-        return None
-
-    c0 = util.bin2int(crc(msg, encode=True))
-    c1 = util.hex2int(msg[-6:])
-    icao = '%06X' % (c0 ^ c1)
-    return icao
-
+    if util.bin2int(d) > 0:
+        return False
+    else:
+        return True
 
 def checkbits(data, sb, msb, lsb):
     """Check if the status bit and field bits are consistency. This Function
@@ -74,9 +58,97 @@ def checkbits(data, sb, msb, lsb):
 
     return True
 
+# ------------------------------------------
+# Common functions
+# ------------------------------------------
+
+def df20alt(msg):
+    """Computes the altitude from DF20 message, bit 20-32
+
+    Args:
+        msg (String): 28 bytes hexadecimal message string
+
+    Returns:
+        int: altitude in ft
+    """
+
+    if util.df(msg) != 20:
+        raise RuntimeError("Message must be Downlink Format 20.")
+
+    return modes_common.altcode(msg)
+
+
+def df21id(msg):
+    """Computes identity (squawk code) from DF21, bit 20-32
+
+    Args:
+        msg (String): 28 bytes hexadecimal message string
+
+    Returns:
+        string: squawk code
+    """
+
+    if util.df(msg) != 21:
+        raise RuntimeError("Message must be Downlink Format 21.")
+
+    return modes_common.idcode(msg)
 
 # ------------------------------------------
-# DF 20/21, BDS 2,0
+# BDS 1,7
+# Common usage GICB capability report
+# ------------------------------------------
+
+def isBDS17(msg):
+    """Check if a message is likely to be BDS code 1,7
+
+    Args:
+        msg (String): 28 bytes hexadecimal message string
+
+    Returns:
+        bool: True or False
+    """
+
+    if isnull(msg):
+        return False
+
+    d = util.hex2bin(data(msg))
+
+    result = True
+
+    if util.bin2int(d[28:56]) != 0:
+        result &= False
+
+    caps = cap17(msg)
+
+    # basic BDS codes for ADS-B shall be supported
+    #   assuming ADS-B out is installed (2017EU/2020US mandate)
+    if not set(['BDS05', 'BDS06', 'BDS09', 'BDS20']).issubset(caps):
+        result &= False
+
+    return result
+
+def cap17(msg):
+    """Extract capacities from BDS 1,7 message
+
+    Args:
+        msg (String): 28 bytes hexadecimal message string
+
+    Returns:
+        list: list of suport BDS codes
+    """
+    allbds = ['05', '06', '07', '08', '09', '0A', '20', '21', '40', '41',
+              '42', '43', '44', '45', '48', '50', '51', '52', '53', '54',
+              '55', '56', '5F', '60', 'NA', 'NA', 'E1', 'E2']
+
+    d = util.hex2bin(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']
+
+    return capacity
+
+# ------------------------------------------
+# BDS 2,0
+# Aircraft identification
 # ------------------------------------------
 
 def isBDS20(msg):
@@ -89,6 +161,9 @@ def isBDS20(msg):
         bool: True or False
     """
 
+    if isnull(msg):
+        return False
+
     # status bit 1, 14, and 27
     d = util.hex2bin(data(msg))
 
@@ -132,7 +207,8 @@ def callsign(msg):
 
 
 # ------------------------------------------
-# DF 20/21, BDS 4,0
+# BDS 4,0
+# Selected vertical intention
 # ------------------------------------------
 
 def isBDS40(msg):
@@ -145,6 +221,9 @@ def isBDS40(msg):
         bool: True or False
     """
 
+    if isnull(msg):
+        return False
+
     # status bit 1, 14, and 27
     d = util.hex2bin(data(msg))
 
@@ -163,7 +242,7 @@ def isBDS40(msg):
     return result
 
 
-def alt_mcp(msg):
+def alt40mcp(msg):
     """Selected altitude, MCP/FCU
 
     Args:
@@ -173,11 +252,15 @@ def alt_mcp(msg):
         int: altitude in feet
     """
     d = util.hex2bin(data(msg))
+
+    if d[0] == '0':
+        return None
+
     alt = util.bin2int(d[1:13]) * 16    # ft
     return alt
 
 
-def alt_fms(msg):
+def alt40fms(msg):
     """Selected altitude, FMS
 
     Args:
@@ -187,11 +270,15 @@ def alt_fms(msg):
         int: altitude in feet
     """
     d = util.hex2bin(data(msg))
+
+    if d[13] == '0':
+        return None
+
     alt = util.bin2int(d[14:26]) * 16    # ft
     return alt
 
 
-def pbaro(msg):
+def p40baro(msg):
     """Barometric pressure setting
 
     Args:
@@ -201,134 +288,206 @@ def pbaro(msg):
         float: pressure in millibar
     """
     d = util.hex2bin(data(msg))
+
+    if d[26] == '0':
+        return None
+
     p = util.bin2int(d[27:39]) * 0.1 + 800    # millibar
     return p
 
 
 # ------------------------------------------
-# DF 20/21, BDS 4,4
+# BDS 4,4
+# Meteorological routine air report
 # ------------------------------------------
 
-def isBDS44(msg):
+def isBDS44(msg, rev=False):
     """Check if a message is likely to be BDS code 4,4
     Meteorological routine air report
 
-    WARNING: there is two different definition for BDS4,4. This part of the
-    decoder is likely to be wrong...
-
     Args:
         msg (String): 28 bytes hexadecimal message string
+        rev (bool): using revised version
 
     Returns:
         bool: True or False
     """
 
-    # status bit 5, 15, 24, 36, 49
+    if isnull(msg):
+        return False
+
     d = util.hex2bin(data(msg))
 
     result = True
 
-    # --- current version ---
-    result = result & checkbits(d, 5, 6, 23) \
-        & checkbits(d, 35, 36, 46) & checkbits(d, 47, 48, 49) \
-        & checkbits(d, 50, 51, 56)
+    if not rev:
+        # status bit 5, 35, 47, 50
+        result = result & checkbits(d, 5, 6, 23) \
+            & checkbits(d, 35, 36, 46) & checkbits(d, 47, 48, 49) \
+            & checkbits(d, 50, 51, 56)
+        # Bits 1-4 indicate source, values > 4 reserved and should not occur
+        if util.bin2int(d[0:4]) > 4:
+            result &= False
+    else:
+        # status bit 5, 15, 24, 36, 49
+        result = result & checkbits(d, 5, 6, 14) \
+            & checkbits(d, 15, 16, 23) & checkbits(d, 24, 25, 35) \
+            & checkbits(d, 36, 37, 47) & checkbits(d, 49, 50, 56)
+        # Bits 1-4 are reserved and should be zero
+        if util.bin2int(d[0:4]) != 0:
+            result &= False
 
-    # # --- revised future version ---
-    # result = result & checkbits(d, 5, 6, 14) \
-    #     & checkbits(d, 15, 16, 23) & checkbits(d, 24, 25, 35) \
-    #     & checkbits(d, 36, 37, 47) & checkbits(d, 49, 50, 56)
+    if not result:
+        return False
 
-    if wind(msg) and wind(msg)[0] > 250:
+    vw = wind44(msg, rev=rev)
+    if vw is not None and vw[0] > 250:
         result &= False
 
-    # if temperature(msg):
-    #     if temperature(msg) > 60 or temperature(msg) < -80:
-    #         result &= False
+    if temp44(msg):
+        if temp44(msg) > 60 or temp44(msg) < -80:
+            result &= False
+    elif temp44(msg) == 0:
+        result &= False
 
     return result
 
 
-def wind(msg):
+def wind44(msg, rev=False):
     """reported wind speed and direction
 
     Args:
         msg (String): 28 bytes hexadecimal message (BDS44) string
+        rev (bool): using revised version
 
     Returns:
         (int, float): speed (kt), direction (degree)
     """
     d = util.hex2bin(data(msg))
 
-    status = int(d[4])
-    if not status:
-        return None
+    if not rev:
+        status = int(d[4])
+        if not status:
+            return None
+
+        speed = util.bin2int(d[5:14])   # knots
+        direction = util.bin2int(d[14:23]) * 180.0 / 256.0  # degree
+
+    else:
+        spd_status = int(d[4])
+        dir_status = int(d[14])
+
+        if (not spd_status) or (not dir_status):
+            return None
+
+        speed = util.bin2int(d[5:14])   # knots
+        direction = util.bin2int(d[15:23]) * 180.0 / 128.0  # degree
 
-    speed = util.bin2int(d[5:14])   # knots
-    direction = util.bin2int(d[14:23]) * 180.0 / 256.0  # degree
     return round(speed, 0), round(direction, 1)
 
 
-def temperature(msg):
+def temp44(msg, rev=False):
     """reported air temperature
 
     Args:
         msg (String): 28 bytes hexadecimal message (BDS44) string
+        rev (bool): using revised version
 
     Returns:
         float: tmeperature in Celsius degree
     """
     d = util.hex2bin(data(msg))
 
-    sign = int(d[23])    # 1 -> minus
-    temp = util.bin2int(d[24:34]) * 0.25   # celsius
-    temp = round(temp, 1)
-    return -1 * temp if sign else temp
+    if not rev:
+        # if d[22] == '0':
+        #     return None
+
+        sign = int(d[23])
+        value = util.bin2int(d[24:34])
+
+        if sign:
+            value = value - 1024
+
+        temp = value * 0.125   # celsius
+        temp = round(temp, 1)
+    else:
+        # if d[23] == '0':
+        #     return None
+
+        sign = int(d[24])
+        value = util.bin2int(d[25:35])
+
+        if sign:
+            value = value - 1024
+
+        temp = value * 0.125   # celsius
+        temp = round(temp, 1)
+
+    return -1*temp if sign else temp
 
 
-def pressure(msg):
+def p44(msg, rev=False):
     """reported average static pressure
 
     Args:
         msg (String): 28 bytes hexadecimal message (BDS44) string
+        rev (bool): using revised version
 
     Returns:
         int: static pressure in hPa
     """
     d = util.hex2bin(data(msg))
 
-    status = int(d[34])
-    if not status:
-        return None
+    if not rev:
+        if d[34] == '0':
+            return None
+
+        p = util.bin2int(d[35:46])    # hPa
+
+    else:
+        if d[35] == '0':
+            return None
+
+        p = util.bin2int(d[36:47])    # hPa
 
-    p = util.bin2int(d[35:46])    # hPa
     return p
 
 
-def humidity(msg):
+def hum44(msg, rev=False):
     """reported humidity
 
     Args:
         msg (String): 28 bytes hexadecimal message (BDS44) string
+        rev (bool): using revised version
 
     Returns:
         float: percentage of humidity, [0 - 100] %
     """
     d = util.hex2bin(data(msg))
 
-    status = int(d[49])
-    if not status:
-        return None
+    if not rev:
+        if d[49] == '0':
+            return None
+
+        hm = util.bin2int(d[50:56]) * 100.0 / 64    # %
+
+    else:
+        if d[48] == '0':
+            return None
+
+        hm = util.bin2int(d[49:56])    # %
 
-    hm = util.bin2int(d[50:56]) * 100.0 / 64    # %
     return round(hm, 1)
 
 
 # ------------------------------------------
-# DF 20/21, BDS 5,0
+# BDS 5,0
+# Track and turn report
 # ------------------------------------------
 
 def isBDS50(msg):
     """Check if a message is likely to be BDS code 5,0
+    (Track and turn report)
 
     Args:
         msg (String): 28 bytes hexadecimal message string
@@ -337,6 +496,9 @@ def isBDS50(msg):
         bool: True or False
     """
 
+    if isnull(msg):
+        return False
+
     # status bit 1, 12, 24, 35, 46
     d = util.hex2bin(data(msg))
 
@@ -346,26 +508,32 @@ def isBDS50(msg):
         & checkbits(d, 24, 25, 34) & checkbits(d, 35, 36, 45) \
         & checkbits(d, 46, 47, 56)
 
+    if not result:
+        return False
+
     if d[2:11] == "000000000":
         result &= True
     else:
-        if abs(roll(msg)) > 30:
+        roll = abs(roll50(msg))
+        if roll and roll > 60:
             result &= False
 
-    if gs(msg) > 500:
+    gs = gs50(msg)
+    if gs is not None and gs > 600:
         result &= False
 
-    if tas(msg) > 500:
+    tas = tas50(msg)
+    if tas is not None and tas > 500:
         result &= False
 
-    if abs(tas(msg) - gs(msg)) > 100:
+    if (gs is not None) and (tas is not None) and (abs(tas - gs) > 200):
         result &= False
 
     return result
 
 
-def roll(msg):
-    """Aircraft roll angle
+def roll50(msg):
+    """Roll angle, BDS 5,0 message
 
     Args:
         msg (String): 28 bytes hexadecimal message (BDS50) string
@@ -375,14 +543,22 @@ def roll(msg):
                negative->left wing down, positive->right wing down
     """
     d = util.hex2bin(data(msg))
+
+    if d[0] == '0':
+        return None
+
     sign = int(d[1])    # 1 -> left wing down
-    value = util.bin2int(d[2:11]) * 45 / 256.0    # degree
-    angle = -1 * value if sign else value
+    value = util.bin2int(d[2:11])
+
+    if sign:
+        value = value - 512
+
+    angle = value * 45.0 / 256.0    # degree
     return round(angle, 1)
 
 
-def track(msg):
-    """True track angle
+def trk50(msg):
+    """True track angle, BDS 5,0 message
 
     Args:
         msg (String): 28 bytes hexadecimal message (BDS50) string
@@ -391,14 +567,27 @@ def track(msg):
         float: angle in degrees to true north (from 0 to 360)
     """
     d = util.hex2bin(data(msg))
+
+    if d[11] == '0':
+        return None
+
     sign = int(d[12])   # 1 -> west
-    value = util.bin2int(d[13:23]) * 90 / 512.0    # degree
-    angle = 360 - value if sign else value
-    return round(angle, 1)
+    value = util.bin2int(d[13:23])
+
+    if sign:
+        value = value - 1024
+
+    trk = value * 90.0 / 512.0
+
+    # convert from [-180, 180] to [0, 360]
+    if trk < 0:
+        trk = 360 + trk
+
+    return round(trk, 1)
 
 
-def gs(msg):
-    """Aircraft ground speed
+def gs50(msg):
+    """Ground speed, BDS 5,0 message
 
     Args:
         msg (String): 28 bytes hexadecimal message (BDS50) string
@@ -407,12 +596,16 @@ def gs(msg):
         int: ground speed in knots
     """
     d = util.hex2bin(data(msg))
+
+    if d[23] == '0':
+        return None
+
     spd = util.bin2int(d[24:34]) * 2    # kts
     return spd
 
 
-def rtrack(msg):
-    """Track angle rate
+def rtrk50(msg):
+    """Track angle rate, BDS 5,0 message
 
     Args:
         msg (String): 28 bytes hexadecimal message (BDS50) string
@@ -421,14 +614,24 @@ def rtrack(msg):
         float: angle rate in degrees/second
     """
     d = util.hex2bin(data(msg))
-    sign = int(d[35])    # 1 -> minus
-    value = util.bin2int(d[36:45]) * 8 / 256.0    # degree / sec
-    angle = -1 * value if sign else value
+
+    if d[34] == '0':
+        return None
+
+    if d[36:45] == "111111111":
+        return None
+
+    sign = int(d[35])    # 1 -> negative value, two's complement
+    value = util.bin2int(d[36:45])
+    if sign:
+        value = value - 512
+
+    angle = value * 8.0 / 256.0    # degree / sec
     return round(angle, 3)
 
 
-def tas(msg):
-    """Aircraft true airspeed
+def tas50(msg):
+    """Aircraft true airspeed, BDS 5,0 message
 
     Args:
         msg (String): 28 bytes hexadecimal message (BDS50) string
@@ -437,12 +640,174 @@ def tas(msg):
         int: true airspeed in knots
     """
     d = util.hex2bin(data(msg))
-    spd = util.bin2int(d[46:56]) * 2   # kts
-    return spd
+
+    if d[45] == '0':
+        return None
+
+    tas = util.bin2int(d[46:56]) * 2   # kts
+    return tas
 
 
 # ------------------------------------------
-# DF 20/21, BDS 6,0
+# BDS 5,3
+# Air-referenced state vector
+# ------------------------------------------
+
+def isBDS53(msg):
+    """Check if a message is likely to be BDS code 5,3
+    (Air-referenced state vector)
+
+    Args:
+        msg (String): 28 bytes hexadecimal message string
+
+    Returns:
+        bool: True or False
+    """
+
+    if isnull(msg):
+        return False
+
+    # status bit 1, 13, 24, 34, 47
+    d = util.hex2bin(data(msg))
+
+    result = True
+
+    result = result & checkbits(d, 1, 3, 12) & checkbits(d, 13, 14, 23) \
+        & checkbits(d, 24, 25, 33) & checkbits(d, 34, 35, 46) \
+        & checkbits(d, 47, 49, 56)
+
+    if not result:
+        return False
+
+    ias = ias53(msg)
+    if ias is not None and ias > 500:
+        result &= False
+
+    mach = mach53(msg)
+    if mach is not None and mach > 1:
+        result &= False
+
+    tas = tas53(msg)
+    if tas is not None and tas > 500:
+        result &= False
+
+    vr = vr53(msg)
+    if vr is not None and abs(vr) > 8000:
+        result &= False
+
+    return result
+
+
+def hdg53(msg):
+    """Magnetic heading, BDS 5,3 message
+
+    Args:
+        msg (String): 28 bytes hexadecimal message (BDS53) string
+
+    Returns:
+        float: angle in degrees to true north (from 0 to 360)
+    """
+    d = util.hex2bin(data(msg))
+
+    if d[0] == '0':
+        return None
+
+    sign = int(d[1])    # 1 -> west
+    value = util.bin2int(d[2:12])
+
+    if sign:
+        value = value - 1024
+
+    hdg = value * 90.0 / 512.0   # degree
+
+    # convert from [-180, 180] to [0, 360]
+    if hdg < 0:
+        hdg = 360 + hdg
+
+    return round(hdg, 1)
+
+
+def ias53(msg):
+    """Indicated airspeed, DBS 5,3 message
+
+    Args:
+        msg (String): 28 bytes hexadecimal message
+
+    Returns:
+        int: indicated arispeed in knots
+    """
+    d = util.hex2bin(data(msg))
+
+    if d[12] == '0':
+        return None
+
+    ias = util.bin2int(d[13:23])    # knots
+    return ias
+
+
+def mach53(msg):
+    """MACH number, DBS 5,3 message
+
+    Args:
+        msg (String): 28 bytes hexadecimal message
+
+    Returns:
+        float: MACH number
+    """
+    d = util.hex2bin(data(msg))
+
+    if d[23] == '0':
+        return None
+
+    mach = util.bin2int(d[24:33]) * 0.008
+    return round(mach, 3)
+
+
+def tas53(msg):
+    """Aircraft true airspeed, BDS 5,3 message
+
+    Args:
+        msg (String): 28 bytes hexadecimal message
+
+    Returns:
+        float: true airspeed in knots
+    """
+    d = util.hex2bin(data(msg))
+
+    if d[33] == '0':
+        return None
+
+    tas = util.bin2int(d[34:46]) * 0.5   # kts
+    return round(tas, 1)
+
+def vr53(msg):
+    """Vertical rate
+
+    Args:
+        msg (String): 28 bytes hexadecimal message (BDS60) string
+
+    Returns:
+        int: vertical rate in feet/minutes
+    """
+    d = util.hex2bin(data(msg))
+
+    if d[46] == '0':
+        return None
+
+    sign = int(d[47])    # 1 -> negative value, two's complement
+    value = util.bin2int(d[48:56])
+
+    if value == 0 or value == 255:  # all zeros or all ones
+        return 0
+
+    value = value - 256 if sign else value
+    roc = value * 64     # feet/min
+
+    return roc
+
+
+# ------------------------------------------
+# BDS 6,0
 # ------------------------------------------
 
 def isBDS60(msg):
@@ -454,6 +819,10 @@ def isBDS60(msg):
     Returns:
         bool: True or False
     """
+
+    if isnull(msg):
+        return False
+
     # status bit 1, 13, 24, 35, 46
     d = util.hex2bin(data(msg))
 
@@ -463,22 +832,24 @@ def isBDS60(msg):
         & checkbits(d, 24, 25, 34) & checkbits(d, 35, 36, 45) \
         & checkbits(d, 46, 47, 56)
 
-    if not (1 < ias(msg) < 500):
+    if not result:
+        return False
+
+    ias = ias60(msg)
+    if ias is not None and ias > 500:
         result &= False
 
-    if not (0.0 < mach(msg) < 1.0):
+    mach = mach60(msg)
+    if mach is not None and mach > 1:
         result &= False
 
-    if abs(baro_vr(msg)) > 5000:
-        result &= False
-
-    if abs(ins_vr(msg)) > 5000:
-        result &= False
+    # leave out the check from vertical rates,
+    #   due to very noisy measurement
 
     return result
 
 
-def heading(msg):
+def hdg60(msg):
     """Megnetic heading of aircraft
 
     Args:
@@ -488,13 +859,26 @@ def heading(msg):
         float: heading in degrees to megnetic north (from 0 to 360)
     """
     d = util.hex2bin(data(msg))
+
+    if d[0] == '0':
+        return None
+
     sign = int(d[1])    # 1 -> west
-    value = util.bin2int(d[2:12]) * 90 / 512.0  # degree
-    hdg = 360 - value if sign else value
+    value = util.bin2int(d[2:12])
+
+    if sign:
+        value = value - 1024
+
+    hdg = value * 90 / 512.0  # degree
+
+    # convert from [-180, 180] to [0, 360]
+    if hdg < 0:
+        hdg = 360 + hdg
+
     return round(hdg, 1)
 
 
-def ias(msg):
+def ias60(msg):
     """Indicated airspeed
 
     Args:
@@ -504,11 +888,15 @@ def ias(msg):
         int: indicated airspeed in knots
     """
     d = util.hex2bin(data(msg))
+
+    if d[12] == '0':
+        return None
+
     ias = util.bin2int(d[13:23])    # kts
     return ias
 
 
-def mach(msg):
+def mach60(msg):
     """Aircraft MACH number
 
     Args:
@@ -518,12 +906,16 @@ def mach(msg):
         float: MACH number
     """
     d = util.hex2bin(data(msg))
+
+    if d[23] == '0':
+        return None
+
     mach = util.bin2int(d[24:34]) * 2.048 / 512.0
     return round(mach, 3)
 
 
-def baro_vr(msg):
-    """Vertical rate from barometric measurement
+def vr60baro(msg):
+    """Vertical rate from barometric measurement, this value may be very noisy.
 
     Args:
         msg (String): 28 bytes hexadecimal message (BDS60) string
@@ -532,13 +924,23 @@ def baro_vr(msg):
         int: vertical rate in feet/minutes
     """
     d = util.hex2bin(data(msg))
-    sign = d[35]    # 1 -> minus
-    value = util.bin2int(d[36:45]) * 32   # feet/min
-    roc = -1*value if sign else value
+
+    if d[34] == '0':
+        return None
+
+    sign = int(d[35])    # 1 -> negative value, two's complement
+    value = util.bin2int(d[36:45])
+
+    if value == 0 or value == 511:  # all zeros or all ones
+        return 0
+
+    value = value - 512 if sign else value
+
+    roc = value * 32   # feet/min
     return roc
 
 
-def ins_vr(msg):
+def vr60ins(msg):
     """Vertical rate messured by onbard equiments (IRS, AHRS)
 
     Args:
@@ -548,9 +950,19 @@ def ins_vr(msg):
         int: vertical rate in feet/minutes
     """
     d = util.hex2bin(data(msg))
-    sign = d[46]    # 1 -> minus
-    value = util.bin2int(d[47:56]) * 32   # feet/min
-    roc = -1*value if sign else value
+
+    if d[45] == '0':
+        return None
+
+    sign = int(d[46])    # 1 -> negative value, two's complement
+    value = util.bin2int(d[47:56])
+
+    if value == 0 or value == 511:  # all zeros or all ones
+        return 0
+
+    value = value - 512 if sign else value
+
+    roc = value * 32   # feet/min
     return roc
 
 
@@ -563,16 +975,25 @@ def BDS(msg):
     Returns:
         String or None: Version: "BDS20", "BDS40", "BDS50", or "BDS60". Or None, if nothing matched
     """
+
+    if isnull(msg):
+        return None
+
+    is17 = isBDS17(msg)
     is20 = isBDS20(msg)
-    is44 = isBDS44(msg)
     is40 = isBDS40(msg)
+    is44 = isBDS44(msg)
+    is44rev = isBDS44(msg, rev=True)
     is50 = isBDS50(msg)
+    is53 = isBDS53(msg)
     is60 = isBDS60(msg)
 
-    BDS = ["BDS20", "BDS40", "BDS44", "BDS50", "BDS60"]
-    isBDS = [is20, is40, is44, is50, is60]
+    BDS = ["BDS17", "BDS20", "BDS40", "BDS44", "BDS44REV", "BDS50", "BDS53", "BDS60"]
+    isBDS = [is17, is20, is40, is44, is44rev, is50, is53, is60]
 
-    if sum(isBDS) == 1:
+    if sum(isBDS) == 0:
+        return None
+    elif sum(isBDS) == 1:
         return BDS[isBDS.index(True)]
     else:
-        return None
+        return [bds for (bds, i) in zip(BDS, isBDS) if i]

pyModeS/els.py

@@ -0,0 +1,37 @@
+from __future__ import absolute_import, print_function, division
+from . import util, modes_common
+
+def icao(msg):
+    return modes_common.icao(msg)
+
+
+def df4alt(msg):
+    """Computes the altitude from DF4 message, bit 20-32
+
+    Args:
+        msg (String): 28 bytes hexadecimal message string
+
+    Returns:
+        int: altitude in ft
+    """
+
+    if util.df(msg) != 4:
+        raise RuntimeError("Message must be Downlink Format 4.")
+
+    return modes_common.altcode(msg)
+
+
+def df5id(msg):
+    """Computes identity (squawk code) from DF5 message, bit 20-32
+
+    Args:
+        msg (String): 28 bytes hexadecimal message string
+
+    Returns:
+        string: squawk code
+    """
+
+    if util.df(msg) != 5:
+        raise RuntimeError("Message must be Downlink Format 5.")
+
+    return modes_common.idcode(msg)

pyModeS/modes_common.py

@@ -0,0 +1,131 @@
+from __future__ import absolute_import, print_function, division
+from . import util
+
+
+def icao(msg):
+    """Calculate the ICAO address from an Mode-S message
+    with DF4, DF5, DF20, DF21
+
+    Args:
+        msg (String): 28 bytes hexadecimal message string
+
+    Returns:
+        String: ICAO address in 6 bytes hexadecimal string
+    """
+
+    if util.df(msg) not in (4, 5, 20, 21):
+        # raise RuntimeError("Message DF must be in (4, 5, 20, 21)")
+        return None
+
+    c0 = util.bin2int(util.crc(msg, encode=True))
+    c1 = util.hex2int(msg[-6:])
+    addr = '%06X' % (c0 ^ c1)
+    return addr
+
+
+def idcode(msg):
+    """Computes identity (squawk code) from DF5 or DF21 message, bit 20-32.
+    credit: @fbyrkjeland
+
+    Args:
+        msg (String): 28 bytes hexadecimal message string
+
+    Returns:
+        string: squawk code
+    """
+
+    if util.df(msg) not in [5, 21]:
+        raise RuntimeError("Message must be Downlink Format 5 or 21.")
+
+    mbin = util.hex2bin(msg)
+
+    C1 = mbin[19]
+    A1 = mbin[20]
+    C2 = mbin[21]
+    A2 = mbin[22]
+    C4 = mbin[23]
+    A4 = mbin[24]
+    # _ = mbin[25]
+    B1 = mbin[26]
+    D1 = mbin[27]
+    B2 = mbin[28]
+    D2 = mbin[29]
+    B4 = mbin[30]
+    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)
+
+    return str(byte1) + str(byte2) + str(byte3) + str(byte4)
+
+
+def altcode(msg):
+    """Computes the altitude from DF4 or DF20 message, bit 20-32.
+    credit: @fbyrkjeland
+
+    Args:
+        msg (String): 28 bytes hexadecimal message string
+
+    Returns:
+        int: altitude in ft
+    """
+
+    if util.df(msg) not in [4, 20]:
+        raise RuntimeError("Message must be Downlink Format 4 or 20.")
+
+    # Altitude code, bit 20-32
+    mbin = util.hex2bin(msg)
+
+    mbit = mbin[25]   # M bit: 26
+    qbit = mbin[27]   # Q bit: 28
+
+
+    if mbit == '0':         # unit in ft
+        if qbit == '1':     # 25ft interval
+            vbin = mbin[19:25] + mbin[26] + mbin[28:32]
+            alt = util.bin2int(vbin) * 25 - 1000
+        if qbit == '0':     # 100ft interval, above 50175ft
+            C1 = mbin[19]
+            A1 = mbin[20]
+            C2 = mbin[21]
+            A2 = mbin[22]
+            C4 = mbin[23]
+            A4 = mbin[24]
+            # _ = mbin[25]
+            B1 = mbin[26]
+            # D1 = mbin[27]     # always zero
+            B2 = mbin[28]
+            D2 = mbin[29]
+            B4 = mbin[30]
+            D4 = mbin[31]
+
+            graystr =  D2 + D4 + A1 + A2 + A4 + B1 + B2 + B4 + C1 + C2 + C4
+            alt = gray2alt(graystr)
+
+    if mbit == '1':         # unit in meter
+        vbin = mbin[19:25] + mbin[26:31]
+        alt = int(util.bin2int(vbin) * 3.28084)  # convert to ft
+
+    return alt
+
+def gray2alt(codestr):
+    gc500 = codestr[:8]
+    n500 = util.gray2int(gc500)
+
+    # in 100-ft step must be converted first
+    gc100 = codestr[8:]
+    n100 = util.gray2int(gc100)
+
+    if n100 in [0, 5, 6]:
+        return None
+
+    if n100 == 7:
+        n100 = 5
+
+    if n500%2:
+        n100 = 6 - n100
+
+    alt = (n500*500 + n100*100) - 1300
+    return alt

pyModeS/util.py

@@ -85,3 +85,13 @@ def floor(x):
         eg.: floor(3.6) = 3, while floor(-3.6) = -4
     """
     return int(math.floor(x))
+
+
+def gray2int(graystr):
+    """Convert greycode to binary (DF4, 20 altitude coding)"""
+    num = bin2int(graystr)
+    num ^= (num >> 8)
+    num ^= (num >> 4)
+    num ^= (num >> 2)
+    num ^= (num >> 1)
+    return num

setup.py

@@ -3,6 +3,13 @@
 See:
 https://packaging.python.org/en/latest/distributing.html
 https://github.com/pypa/sampleproject
+
+Steps for deploying a new verison:
+1. Increase the version number
+2. remove the old deployment under [dist] folder
+3. run: python setup.py sdist
+   run: python setup.py bdist_wheel --universal
+4. twine upload dist/*
 """
 
 # Always prefer setuptools over distutils
@@ -23,7 +30,7 @@ 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='1.0.7',
+    version='1.2.2',
 
     description='Python Mode-S Decoder',
     long_description=long_description,

tests/sample_data_test.py

@@ -1,79 +0,0 @@
-# If you get import error run with ipython
-from pyModeS import adsb
-from pyModeS import ehs
-from pyModeS import util
-
-
-# === Decode sample data file ===
-
-def adsb_decode_all(n=None):
-    print("===== Decode all ADS-B sample data=====")
-    import csv
-    f = open('tests/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)
-
-
-def ehs_decode_all(n=None):
-    print("===== Decode all Mode-S EHS sample data=====")
-    import csv
-    f = open('tests/sample_data_ehs.csv', 'rt')
-    for i, r in enumerate(csv.reader(f)):
-        if n and i > n:
-            break
-
-        ts = r[1]
-        m = r[2]
-        icao = ehs.icao(m)
-        vBDS = ehs.BDS(m)
-
-        if vBDS:
-            if vBDS == "BDS20":
-                print(ts, m, icao, vBDS, ehs.callsign(m))
-
-            if vBDS == "BDS40":
-                print(ts, m, icao, vBDS, ehs.alt_mcp(m),
-                      ehs.alt_fms(m), ehs.pbaro(m))
-
-            if vBDS == "BDS44":
-                print(ts, m, icao, vBDS, ehs.wind(m))
-
-            if vBDS == "BDS50":
-                print(ts, m, icao, vBDS, ehs.roll(m), ehs.track(m),
-                      ehs.gs(m), ehs.rtrack(m), ehs.tas(m))
-
-            if vBDS == "BDS60":
-                print(ts, m, icao, vBDS, ehs.heading(m), ehs.ias(m),
-                      ehs.mach(m), ehs.baro_vr(m), ehs.ins_vr(m))
-        else:
-            print(ts, m, icao, 'UNKNOWN')
-
-if __name__ == '__main__':
-    adsb_decode_all(100)
-    ehs_decode_all(100)

tests/sample_run_adsb.py

@@ -0,0 +1,41 @@
+from __future__ import print_function
+from pyModeS import adsb, ehs, util
+
+
+# === Decode sample data file ===
+
+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)

tests/sample_run_ehs.py

@@ -0,0 +1,75 @@
+from __future__ import print_function
+from pyModeS import adsb, ehs, util
+
+
+# === Decode sample data file ===
+
+def bds_info(BDS, m):
+    if BDS == "BDS17":
+        info = ([i[-2:] for i in ehs.cap17(m)])
+
+    elif BDS == "BDS20":
+        info = ehs.callsign(m)
+
+    elif BDS == "BDS40":
+        info = (ehs.alt40mcp(m), ehs.alt40fms(m), ehs.p40baro(m))
+
+    elif BDS == "BDS44":
+        info = (ehs.wind44(m), ehs.temp44(m), ehs.p44(m), ehs.hum44(m))
+
+    elif BDS == "BDS44REV":
+        info = (ehs.wind44(m, rev=True), ehs.temp44(m, rev=True), ehs.p44(m, rev=True), ehs.hum44(m, rev=True))
+
+    elif BDS == "BDS50":
+        info = (ehs.roll50(m), ehs.trk50(m), ehs.gs50(m), ehs.rtrk50(m), ehs.tas50(m))
+
+    elif BDS == "BDS53":
+        info = (ehs.hdg53(m), ehs.ias53(m), ehs.mach53(m), ehs.tas53(m), ehs.vr53(m))
+
+    elif BDS == "BDS60":
+        info = (ehs.hdg60(m), ehs.ias60(m), ehs.mach60(m), ehs.vr60baro(m), ehs.vr60ins(m))
+
+    else:
+        info = None
+
+    return info
+
+
+def ehs_decode_all(df, n=None):
+    import csv
+
+    print("===== Decode EHS sample data (DF=%s)=====" % df)
+
+    f = open('tests/data/sample_data_ehs_df%s.csv' % df, 'rt')
+
+
+    for i, r in enumerate(csv.reader(f)):
+        if n and i > n:
+            break
+
+        ts = r[0]
+        m = r[2]
+
+        df = util.df(m)
+        icao = ehs.icao(m)
+        BDS = ehs.BDS(m)
+        code = ehs.df20alt(m) if df==20 else ehs.df21id(m)
+
+        if not BDS:
+            print(ts, m, icao, df, '%5s'%code, 'UNKNOWN')
+            continue
+
+        if isinstance(BDS, list):
+            print(ts, m, icao, df, '%5s'%code, end=' ')
+            for i, bds in enumerate(BDS):
+                if i == 0:
+                    print(bds, *bds_info(bds, m))
+                else:
+                    print(' '*55, bds, *bds_info(bds, m))
+
+        else:
+            print(ts, m, icao, df, '%5s'%code, BDS, *bds_info(BDS, m))
+
+if __name__ == '__main__':
+    ehs_decode_all(df=20, n=100)
+    ehs_decode_all(df=21, n=100)

tests/test_adsb.py

@@ -1,6 +1,5 @@
 from pyModeS import adsb
 
-
 # === TEST ADS-B package ===
 
 def test_adsb_icao():
@@ -22,6 +21,13 @@ def test_adsb_position():
     assert pos == (49.81755, 6.08442)
 
 
+def test_adsb_position_with_ref():
+    pos = adsb.position_with_ref("8D40058B58C901375147EFD09357", 49.0, 6.0)
+    assert pos == (49.82410, 6.06785)
+    pos = adsb.position_with_ref("8FC8200A3AB8F5F893096B000000", -43.5, 172.5)
+    assert pos == (-43.48564, 172.53942)
+
+
 def test_adsb_airborne_position_with_ref():
     pos = adsb.airborne_position_with_ref("8D40058B58C901375147EFD09357",
                                           49.0, 6.0)
@@ -32,9 +38,9 @@ def test_adsb_airborne_position_with_ref():
 
 
 def test_adsb_surface_position_with_ref():
-    pos = adsb.surface_position_with_ref("8FC8200A3AB8F5F893096B22B4A8",
+    pos = adsb.surface_position_with_ref("8FC8200A3AB8F5F893096B000000",
                                          -43.5, 172.5)
-    assert pos == (-43.48564, 175.87195)
+    assert pos == (-43.48564, 172.53942)
 
 
 def test_adsb_surface_position():
@@ -51,8 +57,11 @@ def test_adsb_alt():
 def test_adsb_velocity():
     vgs = adsb.velocity("8D485020994409940838175B284F")
     vas = adsb.velocity("8DA05F219B06B6AF189400CBC33F")
+    vgs_surface = adsb.velocity("8FC8200A3AB8F5F893096B000000")
     assert vgs == (159, 182.9, -832, 'GS')
     assert vas == (376, 244.0, -2304, 'AS')
+    assert vgs_surface == (19.0, 42.2, 0 , 'GS')
+    assert adsb.altitude_diff('8D485020994409940838175B284F') == 550
 
 
 def test_nic():

tests/test_ehs.py

@@ -1,5 +1,5 @@
 from pyModeS import ehs
-
+from pyModeS import modes_common
 
 def test_ehs_icao():
     assert ehs.icao("A0001839CA3800315800007448D9") == '400940'
@@ -7,14 +7,16 @@ def test_ehs_icao():
     assert ehs.icao("A000029CFFBAA11E2004727281F1") == '4243D0'
 
 
+def test_df20alt():
+    assert ehs.df20alt("A02014B400000000000000F9D514") == 32300
+
+
 def test_ehs_BDS():
     assert ehs.BDS("A0001838201584F23468207CDFA5") == 'BDS20'
     assert ehs.BDS("A0001839CA3800315800007448D9") == 'BDS40'
+    # assert ehs.BDS("A000031DBAA9DD18622C441330E9") == 'BDS44'
     assert ehs.BDS("A000139381951536E024D4CCF6B5") == 'BDS50'
-    assert ehs.BDS("A000029CFFBAA11E2004727281F1") == 'BDS60'
-    assert ehs.BDS("A0281838CAE9E12FA03FFF2DDDE5") == 'BDS44'
-    assert ehs.BDS("A00017B0C8480030A4000024512F") is None
-
+    assert ehs.BDS("A00004128F39F91A7E27C46ADC21") == 'BDS60'
 
 def test_ehs_BDS20_callsign():
     assert ehs.callsign("A000083E202CC371C31DE0AA1CCF") == 'KLM1017_'
@@ -22,22 +24,39 @@ def test_ehs_BDS20_callsign():
 
 
 def test_ehs_BDS40_functions():
-    assert ehs.alt_mcp("A000029C85E42F313000007047D3") == 3008
-    assert ehs.alt_fms("A000029C85E42F313000007047D3") == 3008
-    assert ehs.pbaro("A000029C85E42F313000007047D3") == 1020.0
-
+    assert ehs.alt40mcp("A000029C85E42F313000007047D3") == 3008
+    assert ehs.alt40fms("A000029C85E42F313000007047D3") == 3008
+    assert ehs.p40baro("A000029C85E42F313000007047D3") == 1020.0
 
 def test_ehs_BDS50_functions():
-    assert ehs.roll("A000139381951536E024D4CCF6B5") == 2.1
-    assert ehs.track("A000139381951536E024D4CCF6B5") == 114.3
-    assert ehs.gs("A000139381951536E024D4CCF6B5") == 438
-    assert ehs.rtrack("A000139381951536E024D4CCF6B5") == 0.125
-    assert ehs.tas("A000139381951536E024D4CCF6B5") == 424
-
+    assert ehs.roll50("A000139381951536E024D4CCF6B5") == 2.1
+    assert ehs.trk50("A000139381951536E024D4CCF6B5") == 114.3
+    assert ehs.gs50("A000139381951536E024D4CCF6B5") == 438
+    assert ehs.rtrk50("A000139381951536E024D4CCF6B5") == 0.125
+    assert ehs.tas50("A000139381951536E024D4CCF6B5") == 424
+    # signed values
+    assert ehs.roll50("A0001691FFD263377FFCE02B2BF9") == -0.4
 
 def test_ehs_BDS60_functions():
-    assert ehs.heading("A000029CFFBAA11E2004727281F1") == 180.9
-    assert ehs.ias("A000029CFFBAA11E2004727281F1") == 336
-    assert ehs.mach("A000029CFFBAA11E2004727281F1") == 0.48
-    assert ehs.baro_vr("A000029CFFBAA11E2004727281F1") == 0
-    assert ehs.ins_vr("A000029CFFBAA11E2004727281F1") == -3648
+    assert ehs.hdg60("A00004128F39F91A7E27C46ADC21") == 42.7
+    assert ehs.ias60("A00004128F39F91A7E27C46ADC21") == 252
+    assert ehs.mach60("A00004128F39F91A7E27C46ADC21") == 0.42
+    assert ehs.vr60baro("A00004128F39F91A7E27C46ADC21") == -1920
+    assert ehs.vr60ins("A00004128F39F91A7E27C46ADC21") == -1920
+
+def test_graycode_to_altitude():
+    assert modes_common.gray2alt('00000000010') == -1000
+    assert modes_common.gray2alt('00000001010') == -500
+    assert modes_common.gray2alt('00000011011') == -100
+    assert modes_common.gray2alt('00000011010') == 0
+    assert modes_common.gray2alt('00000011110') == 100
+    assert modes_common.gray2alt('00000010011') == 600
+    assert modes_common.gray2alt('00000110010') == 1000
+    assert modes_common.gray2alt('00001001001') == 5800
+    assert modes_common.gray2alt('00011100100') == 10300
+    assert modes_common.gray2alt('01100011010') == 32000
+    assert modes_common.gray2alt('01110000100') == 46300
+    assert modes_common.gray2alt('01010101100') == 50200
+    assert modes_common.gray2alt('11011110100') == 73200
+    assert modes_common.gray2alt('10000000011') == 126600
+    assert modes_common.gray2alt('10000000001') == 126700

tests/test_util.py

@@ -12,4 +12,4 @@ def test_crc_decode():
 
 def test_crc_encode():
     parity = util.crc("8D406B902015A678D4D220AA4BDA", encode=True)
-    assert util.hex2bin("AA4BDA") == parity
+    assert util.hex2bin("AA4BDA") == parity

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 toxworkdir=/tmp/tox
-envlist = py26,py27,py35
+envlist = py2,py3
 [testenv]
 deps=pytest
 commands=py.test