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Refactoring

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This commit is contained in:
nzkarit
2017-09-08 21:27:36 +12:00
parent 15744fcc32
commit 6cc86f78c5
3 changed files with 106 additions and 99 deletions
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10
ModeS.py
View File

@@ -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)
(oddenclat, oddenclon) = cpr_encode(lat, lon, True, surface)
(evenenclat, evenenclon) = location.cpr_encode(lat, lon, False, 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)

100
ModeSLocation.py Normal file
View File

@@ -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

95
location.py
View File

@@ -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