Merge pull request #2 from nzkarit/refactor2

Refactor2

ModeS.py

@@ -1,4 +1,5 @@
-from location import *
+from ModeSLocation import ModeSLocation
+import math
 
 class ModeS:
     """This class handles the ModeS ADSB manipulation
@@ -11,12 +12,13 @@ class ModeS:
 
         format = 17 #The format type of an ADSB message
 
-        enc_alt =	encode_alt_modes(alt, surface)
+        location = ModeSLocation()
+        enc_alt =	location.encode_alt_modes(alt, surface)
         #print "Alt(%r): %X " % (surface, enc_alt)
 
         #encode that position
-        (evenenclat, evenenclon) = cpr_encode(lat, lon, False, surface)
+        (evenenclat, evenenclon) = location.cpr_encode(lat, lon, False, surface)
-        (oddenclat, oddenclon)   = cpr_encode(lat, lon, True, surface)
+        (oddenclat, oddenclon)   = location.cpr_encode(lat, lon, True, surface)
 
         #print "Even Lat/Lon: %X/%X " % (evenenclat, evenenclon)
         #print "Odd  Lat/Lon: %X/%X " % (oddenclat, oddenclon)

ModeSLocation.py

@@ -0,0 +1,100 @@
+import math
+
+class ModeSLocation:
+    """This class does ModeS/ADSB Location calulations"""
+
+    
+    
+##########################################################################
+
+# Copyright 2010, 2012 Nick Foster
+# 
+# This file is part of gr-air-modes
+# 
+# gr-air-modes 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, or (at your option)
+# any later version.
+# 
+# gr-air-modes 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 gr-air-modes; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+# 
+
+    def encode_alt_modes(self, alt, bit13):
+        mbit = False
+        qbit = True
+        encalt = (int(alt) + 1000) / 25
+
+        if bit13 is True:
+            tmp1 = (encalt & 0xfe0) << 2
+            tmp2 = (encalt & 0x010) << 1
+
+        else:
+            tmp1 = (encalt & 0xff8) << 1
+            tmp2 = 0
+
+        return (encalt & 0x0F) | tmp1 | tmp2 | (mbit << 6) | (qbit << 4)
+
+    latz = 15
+
+    def nz(self, ctype):
+	    """
+	    Number of geographic latitude zones between equator and a pole. It is set to NZ = 15 for Mode-S CPR encoding
+	    https://adsb-decode-guide.readthedocs.io/en/latest/content/cpr.html
+	    """
+	    return 4 * self.latz - ctype
+
+    def dlat(self, ctype, surface):
+	    if surface == 1:
+		    tmp = 90.0
+	    else:
+		    tmp = 360.0
+
+	    nzcalc = self.nz(ctype)
+	    if nzcalc == 0:
+		    return tmp
+	    else:
+		    return tmp / nzcalc
+
+    def nl(self, declat_in):
+	    if abs(declat_in) >= 87.0:
+		    return 1.0
+	    return math.floor( (2.0*math.pi) * math.acos(1.0- (1.0-math.cos(math.pi/(2.0*self.latz))) / math.cos( (math.pi/180.0)*abs(declat_in) )**2 )**-1)
+
+    def dlon(self, declat_in, ctype, surface):
+	    if surface:
+		    tmp = 90.0
+	    else:
+		    tmp = 360.0
+	    nlcalc = max(self.nl(declat_in)-ctype, 1)
+	    return tmp / nlcalc
+
+    #encode CPR position
+    # https://adsb-decode-guide.readthedocs.io/en/latest/content/cpr.html
+    # compact position reporting
+    def cpr_encode(self, lat, lon, ctype, surface):
+        if surface is True:
+            scalar = 2.**19
+        else:
+            scalar = 2.**17
+
+        #encode using 360 constant for segment size.
+        dlati = self.dlat(ctype, False)
+        yz = math.floor(scalar * ((lat % dlati)/dlati) + 0.5)
+        rlat = dlati * ((yz / scalar) + math.floor(lat / dlati))
+        
+        #encode using 360 constant for segment size.
+        dloni = self.dlon(lat, ctype, False)
+        xz = math.floor(scalar * ((lon % dloni)/dloni) + 0.5)
+        
+        yz = int(yz) & (2**17-1)
+        xz = int(xz) & (2**17-1)
+        
+        return (yz, xz) #lat, lon

README.md

@@ -16,15 +16,7 @@ $ ls Samples.iq8s
 Samples.iq8s
 $
 ```
-2. Make the raw signal file aligned to 256K buffer size:
+2. Transmit the signal into air:
-```
-$ dd if=Samples.iq8s of=Samples_256K.iq8s bs=4k seek=63
-1+0 records in
-1+0 records out
-4096 bytes (4.1 kB) copied, 0.00110421 s, 3.7 MB/s
-$
-```
-3. Transmit the signal into air:
 ```
 $ hackrf_transfer -t Samples_256K.iq8s -f 868000000 -s 2000000 -x 10
 call hackrf_sample_rate_set(2000000 Hz/2.000 MHz)

conversions.py

@@ -1,6 +0,0 @@
-
-import math
-
-
-
-

location.py

@@ -1,95 +0,0 @@
-##########################################################################
-
-# Copyright 2010, 2012 Nick Foster
-# 
-# This file is part of gr-air-modes
-# 
-# gr-air-modes 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, or (at your option)
-# any later version.
-# 
-# gr-air-modes 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 gr-air-modes; see the file COPYING.  If not, write to
-# the Free Software Foundation, Inc., 51 Franklin Street,
-# Boston, MA 02110-1301, USA.
-# 
-
-import math
-
-def encode_alt_modes(alt, bit13):
-    mbit = False
-    qbit = True
-    encalt = (int(alt) + 1000) / 25
-
-    if bit13 is True:
-        tmp1 = (encalt & 0xfe0) << 2
-        tmp2 = (encalt & 0x010) << 1
-
-    else:
-        tmp1 = (encalt & 0xff8) << 1
-        tmp2 = 0
-
-    return (encalt & 0x0F) | tmp1 | tmp2 | (mbit << 6) | (qbit << 4)
-
-latz = 15
-
-def nz(ctype):
-	"""
-	Number of geographic latitude zones between equator and a pole. It is set to NZ = 15 for Mode-S CPR encoding
-	https://adsb-decode-guide.readthedocs.io/en/latest/content/cpr.html
-	"""
-	return 4 * latz - ctype
-
-def dlat(ctype, surface):
-	if surface == 1:
-		tmp = 90.0
-	else:
-		tmp = 360.0
-
-	nzcalc = nz(ctype)
-	if nzcalc == 0:
-		return tmp
-	else:
-		return tmp / nzcalc
-
-def nl(declat_in):
-	if abs(declat_in) >= 87.0:
-		return 1.0
-	return math.floor( (2.0*math.pi) * math.acos(1.0- (1.0-math.cos(math.pi/(2.0*latz))) / math.cos( (math.pi/180.0)*abs(declat_in) )**2 )**-1)
-
-def dlon(declat_in, ctype, surface):
-	if surface:
-		tmp = 90.0
-	else:
-		tmp = 360.0
-	nlcalc = max(nl(declat_in)-ctype, 1)
-	return tmp / nlcalc
-
-#encode CPR position
-# https://adsb-decode-guide.readthedocs.io/en/latest/content/cpr.html
-# compact position reporting
-def cpr_encode(lat, lon, ctype, surface):
-    if surface is True:
-        scalar = 2.**19
-    else:
-        scalar = 2.**17
-
-    #encode using 360 constant for segment size.
-    dlati = dlat(ctype, False)
-    yz = math.floor(scalar * ((lat % dlati)/dlati) + 0.5)
-    rlat = dlati * ((yz / scalar) + math.floor(lat / dlati))
-    
-    #encode using 360 constant for segment size.
-    dloni = dlon(lat, ctype, False)
-    xz = math.floor(scalar * ((lon % dloni)/dloni) + 0.5)
-    
-    yz = int(yz) & (2**17-1)
-    xz = int(xz) & (2**17-1)
-    
-    return (yz, xz) #lat, lon

parity.py

@@ -1,49 +0,0 @@
-'''
-   Copyright 2015 Wolfgang Nagele
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
-'''
-def bin2dec(buf):
-  if 0 == len(buf): # Crap input
-    return -1
-  return int(buf, 2)
-
-# Ported from: http://www.radarspotters.eu/forum/index.php?topic=5617.msg41293#msg41293
-def get_parity(msg, extended):
-  msg_length = len(msg)
-  payload = msg[:msg_length - 24]
-  parity = msg[msg_length - 24:]
-
-  data = bin2dec(payload[0:32])
-  if extended:
-    data1 = bin2dec(payload[32:64])
-    data2 = bin2dec(payload[64:]) << 8
-
-  hex_id = bin2dec(parity) << 8
-
-  for i in range(0, len(payload)):
-    if ((data & 0x80000000) != 0):
-      data ^= 0xFFFA0480
-    data <<= 1
-
-    if extended:
-      if ((data1 & 0x80000000) != 0):
-        data |= 1
-      data1 <<= 1
-
-      if ((data2 & 0x80000000) != 0):
-        data1 = data1 | 1
-      data2 <<= 1
-
-  return data
-  #return (data ^ hex_id) >> 8