Moving code around to help my understanding. file names most probably wrong right now but will update when understand it better
This commit is contained in:
parent
22ed603fd3
commit
960a697976
239
ADSB_Encoder.py
239
ADSB_Encoder.py
@ -1,250 +1,19 @@
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#!/usr/bin/env python
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#!/usr/bin/env python
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#
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#
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##########################################################################
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from encoder import *
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from location import *
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from conversions import *
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from parity import *
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# Copyright 2010, 2012 Nick Foster
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#
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# This file is part of gr-air-modes
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#
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# gr-air-modes is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; either version 3, or (at your option)
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# any later version.
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#
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# gr-air-modes is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with gr-air-modes; see the file COPYING. If not, write to
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# the Free Software Foundation, Inc., 51 Franklin Street,
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# Boston, MA 02110-1301, USA.
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#
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import math
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def encode_alt_modes(alt, bit13):
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mbit = False
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qbit = True
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encalt = (int(alt) + 1000) / 25
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if bit13 is True:
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tmp1 = (encalt & 0xfe0) << 2
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tmp2 = (encalt & 0x010) << 1
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else:
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tmp1 = (encalt & 0xff8) << 1
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tmp2 = 0
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return (encalt & 0x0F) | tmp1 | tmp2 | (mbit << 6) | (qbit << 4)
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latz = 15
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def nz(ctype):
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return 4 * latz - ctype
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def dlat(ctype, surface):
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if surface == 1:
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tmp = 90.0
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else:
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tmp = 360.0
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nzcalc = nz(ctype)
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if nzcalc == 0:
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return tmp
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else:
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return tmp / nzcalc
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def nl(declat_in):
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if abs(declat_in) >= 87.0:
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return 1.0
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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)
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def dlon(declat_in, ctype, surface):
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if surface:
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tmp = 90.0
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else:
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tmp = 360.0
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nlcalc = max(nl(declat_in)-ctype, 1)
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return tmp / nlcalc
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#encode CPR position
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def cpr_encode(lat, lon, ctype, surface):
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if surface is True:
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scalar = 2.**19
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else:
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scalar = 2.**17
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#encode using 360 constant for segment size.
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dlati = dlat(ctype, False)
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yz = math.floor(scalar * ((lat % dlati)/dlati) + 0.5)
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rlat = dlati * ((yz / scalar) + math.floor(lat / dlati))
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#encode using 360 constant for segment size.
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dloni = dlon(lat, ctype, False)
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xz = math.floor(scalar * ((lon % dloni)/dloni) + 0.5)
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yz = int(yz) & (2**17-1)
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xz = int(xz) & (2**17-1)
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return (yz, xz) #lat, lon
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###############################################################
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###############################################################
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# Copyright (C) 2015 Junzi Sun (TU Delft)
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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# the polynominal generattor code for CRC
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GENERATOR = "1111111111111010000001001"
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def hex2bin(hexstr):
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"""Convert a hexdecimal string to binary string, with zero fillings. """
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scale = 16
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num_of_bits = len(hexstr) * math.log(scale, 2)
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binstr = bin(int(hexstr, scale))[2:].zfill(int(num_of_bits))
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return binstr
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def bin2int(binstr):
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"""Convert a binary string to integer. """
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return int(binstr, 2)
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def crc(msg, encode=False):
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"""Mode-S Cyclic Redundancy Check
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Detect if bit error occurs in the Mode-S message
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Args:
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msg (string): 28 bytes hexadecimal message string
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encode (bool): True to encode the date only and return the checksum
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Returns:
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string: message checksum, or partity bits (encoder)
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"""
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msgbin = list(hex2bin(msg))
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if encode:
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msgbin[-24:] = ['0'] * 24
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# loop all bits, except last 24 piraty bits
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for i in range(len(msgbin)-24):
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# if 1, perform modulo 2 multiplication,
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if msgbin[i] == '1':
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for j in range(len(GENERATOR)):
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# modulo 2 multiplication = XOR
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msgbin[i+j] = str((int(msgbin[i+j]) ^ int(GENERATOR[j])))
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# last 24 bits
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reminder = ''.join(msgbin[-24:])
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return reminder
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###############################################################
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###############################################################
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'''
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Copyright 2015 Wolfgang Nagele
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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'''
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def bin2dec(buf):
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if 0 == len(buf): # Crap input
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return -1
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return int(buf, 2)
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# Ported from: http://www.radarspotters.eu/forum/index.php?topic=5617.msg41293#msg41293
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def get_parity(msg, extended):
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msg_length = len(msg)
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payload = msg[:msg_length - 24]
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parity = msg[msg_length - 24:]
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data = bin2dec(payload[0:32])
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if extended:
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data1 = bin2dec(payload[32:64])
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data2 = bin2dec(payload[64:]) << 8
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hex_id = bin2dec(parity) << 8
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for i in range(0, len(payload)):
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if ((data & 0x80000000) != 0):
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data ^= 0xFFFA0480
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data <<= 1
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if extended:
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if ((data1 & 0x80000000) != 0):
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data |= 1
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data1 <<= 1
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if ((data2 & 0x80000000) != 0):
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data1 = data1 | 1
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data2 <<= 1
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return data
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#return (data ^ hex_id) >> 8
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###############################################################
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"""
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Hamming and Manchester Encoding example
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Author: Joel Addison
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Date: March 2013
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Functions to do (7,4) hamming encoding and decoding, including error detection
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and correction.
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Manchester encoding and decoding is also included, and by default will use
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least bit ordering for the byte that is to be included in the array.
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"""
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def extract_bit(byte, pos):
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"""
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Extract a bit from a given byte using MS ordering.
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ie. B7 B6 B5 B4 B3 B2 B1 B0
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"""
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return (byte >> pos) & 0x01
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def manchester_encode(byte):
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"""
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Encode a byte using Manchester encoding. Returns an array of bits.
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Adds two start bits (1, 1) and one stop bit (0) to the array.
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"""
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# Add start bits (encoded 1, 1)
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# manchester_encoded = [0, 1, 0, 1]
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manchester_encoded = []
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# Encode byte
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for i in range(7, -1, -1):
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if extract_bit(byte, i):
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manchester_encoded.append(0)
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manchester_encoded.append(1)
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else:
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manchester_encoded.append(1)
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manchester_encoded.append(0)
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# Add stop bit (encoded 0)
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# manchester_encoded.append(1)
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# manchester_encoded.append(0)
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return manchester_encoded
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###############################################################
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###############################################################
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59
conversions.py
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59
conversions.py
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###############################################################
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# Copyright (C) 2015 Junzi Sun (TU Delft)
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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# the polynominal generattor code for CRC
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import math
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GENERATOR = "1111111111111010000001001"
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def hex2bin(hexstr):
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"""Convert a hexdecimal string to binary string, with zero fillings. """
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scale = 16
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num_of_bits = len(hexstr) * math.log(scale, 2)
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binstr = bin(int(hexstr, scale))[2:].zfill(int(num_of_bits))
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return binstr
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def bin2int(binstr):
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"""Convert a binary string to integer. """
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return int(binstr, 2)
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def crc(msg, encode=False):
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"""Mode-S Cyclic Redundancy Check
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Detect if bit error occurs in the Mode-S message
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Args:
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msg (string): 28 bytes hexadecimal message string
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encode (bool): True to encode the date only and return the checksum
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Returns:
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string: message checksum, or partity bits (encoder)
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"""
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msgbin = list(hex2bin(msg))
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if encode:
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msgbin[-24:] = ['0'] * 24
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# loop all bits, except last 24 piraty bits
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for i in range(len(msgbin)-24):
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# if 1, perform modulo 2 multiplication,
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if msgbin[i] == '1':
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for j in range(len(GENERATOR)):
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# modulo 2 multiplication = XOR
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msgbin[i+j] = str((int(msgbin[i+j]) ^ int(GENERATOR[j])))
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# last 24 bits
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reminder = ''.join(msgbin[-24:])
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return reminder
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42
encoder.py
Normal file
42
encoder.py
Normal file
@ -0,0 +1,42 @@
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"""
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Hamming and Manchester Encoding example
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Author: Joel Addison
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Date: March 2013
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Functions to do (7,4) hamming encoding and decoding, including error detection
|
||||||
|
and correction.
|
||||||
|
Manchester encoding and decoding is also included, and by default will use
|
||||||
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least bit ordering for the byte that is to be included in the array.
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"""
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def extract_bit(byte, pos):
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"""
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Extract a bit from a given byte using MS ordering.
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ie. B7 B6 B5 B4 B3 B2 B1 B0
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"""
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return (byte >> pos) & 0x01
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def manchester_encode(byte):
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"""
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Encode a byte using Manchester encoding. Returns an array of bits.
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Adds two start bits (1, 1) and one stop bit (0) to the array.
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"""
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# Add start bits (encoded 1, 1)
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# manchester_encoded = [0, 1, 0, 1]
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manchester_encoded = []
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# Encode byte
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for i in range(7, -1, -1):
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if extract_bit(byte, i):
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manchester_encoded.append(0)
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manchester_encoded.append(1)
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else:
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manchester_encoded.append(1)
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manchester_encoded.append(0)
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# Add stop bit (encoded 0)
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# manchester_encoded.append(1)
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# manchester_encoded.append(0)
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return manchester_encoded
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89
location.py
Normal file
89
location.py
Normal file
@ -0,0 +1,89 @@
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##########################################################################
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# Copyright 2010, 2012 Nick Foster
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||||||
|
#
|
||||||
|
# This file is part of gr-air-modes
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||||||
|
#
|
||||||
|
# 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)
|
||||||
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# 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,
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||||||
|
# Boston, MA 02110-1301, USA.
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||||||
|
#
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||||||
|
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||||||
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import math
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|
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||||||
|
def encode_alt_modes(alt, bit13):
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||||||
|
mbit = False
|
||||||
|
qbit = True
|
||||||
|
encalt = (int(alt) + 1000) / 25
|
||||||
|
|
||||||
|
if bit13 is True:
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||||||
|
tmp1 = (encalt & 0xfe0) << 2
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tmp2 = (encalt & 0x010) << 1
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||||||
|
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||||||
|
else:
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tmp1 = (encalt & 0xff8) << 1
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tmp2 = 0
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return (encalt & 0x0F) | tmp1 | tmp2 | (mbit << 6) | (qbit << 4)
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|
latz = 15
|
||||||
|
|
||||||
|
def nz(ctype):
|
||||||
|
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
|
||||||
|
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
|
49
parity.py
Normal file
49
parity.py
Normal file
@ -0,0 +1,49 @@
|
|||||||
|
'''
|
||||||
|
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
|
Loading…
Reference in New Issue
Block a user