74 lines
1.9 KiB
Python
74 lines
1.9 KiB
Python
# Copyright (C) 2018 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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from __future__ import absolute_import, print_function, division
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from pyModeS.decoder.common import hex2bin, bin2int, data, allzeros
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# ------------------------------------------
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# BDS 2,0
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# Aircraft identification
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# ------------------------------------------
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def is20(msg):
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"""Check if a message is likely to be BDS code 2,0
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Args:
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msg (String): 28 bytes hexadecimal message string
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Returns:
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bool: True or False
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"""
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if allzeros(msg):
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return False
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d = hex2bin(data(msg))
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if d[0:8] != '00100000':
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return False
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cs = cs20(msg)
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if '#' in cs:
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return False
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return True
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def cs20(msg):
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"""Aircraft callsign
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Args:
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msg (String): 28 bytes hexadecimal message (BDS40) string
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Returns:
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string: callsign, max. 8 chars
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"""
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chars = '#ABCDEFGHIJKLMNOPQRSTUVWXYZ#####_###############0123456789######'
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d = hex2bin(data(msg))
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cs = ''
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cs += chars[bin2int(d[8:14])]
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cs += chars[bin2int(d[14:20])]
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cs += chars[bin2int(d[20:26])]
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cs += chars[bin2int(d[26:32])]
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cs += chars[bin2int(d[32:38])]
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cs += chars[bin2int(d[38:44])]
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cs += chars[bin2int(d[44:50])]
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cs += chars[bin2int(d[50:56])]
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return cs
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