60 lines
1.2 KiB
Python
60 lines
1.2 KiB
Python
# ------------------------------------------
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# BDS 2,0
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# Aircraft identification
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# ------------------------------------------
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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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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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