def is40(msg):
"""Check if a message is likely to be BDS code 4,0
Args:
msg (String): 28 bytes hexadecimal message string
Returns:
bool: True or False
"""
if allzeros(msg):
return False
d = hex2bin(data(msg))
# status bit 1, 14, and 27
if wrongstatus(d, 1, 2, 13):
return False
if wrongstatus(d, 14, 15, 26):
return False
if wrongstatus(d, 27, 28, 39):
return False
if wrongstatus(d, 48, 49, 51):
return False
if wrongstatus(d, 54, 55, 56):
return False
# bits 40-47 and 52-53 shall all be zero
if bin2int(d[39:47]) != 0:
return False
if bin2int(d[51:53]) != 0:
return False
return True
def temp45(msg):
"""Static air temperature.
Args:
msg (String): 28 bytes hexadecimal message string
Returns:
float: tmeperature in Celsius degree
"""
d = hex2bin(data(msg))
sign = int(d[16])
value = bin2int(d[17:26])
if sign:
value = value - 512
temp = value * 0.25 # celsius
temp = round(temp, 1)
return temp
def temp44(msg, rev=False):
"""reported air temperature
Args:
msg (String): 28 bytes hexadecimal message (BDS44) string
rev (bool): using revised version
Returns:
float: tmeperature in Celsius degree
"""
d = hex2bin(data(msg))
if not rev:
# if d[22] == '0':
# return None
sign = int(d[23])
value = bin2int(d[24:34])
if sign:
value = value - 1024
temp = value * 0.125 # celsius
temp = round(temp, 1)
else:
# if d[23] == '0':
# return None
sign = int(d[24])
value = bin2int(d[25:35])
if sign:
value = value - 1024
temp = value * 0.125 # celsius
temp = round(temp, 1)
return temp
def roll50(msg):
"""Roll angle, BDS 5,0 message
Args:
msg (String): 28 bytes hexadecimal message (BDS50) string
Returns:
float: angle in degrees,
negative->left wing down, positive->right wing down
"""
d = hex2bin(data(msg))
if d[0] == '0':
return None
sign = int(d[1]) # 1 -> left wing down
value = bin2int(d[2:11])
if sign:
value = value - 512
angle = value * 45.0 / 256.0 # degree
return round(angle, 1)
def rtrk50(msg):
"""Track angle rate, BDS 5,0 message
Args:
msg (String): 28 bytes hexadecimal message (BDS50) string
Returns:
float: angle rate in degrees/second
"""
d = hex2bin(data(msg))
if d[34] == '0':
return None
if d[36:45] == "111111111":
return None
sign = int(d[35]) # 1 -> negative value, two's complement
value = bin2int(d[36:45])
if sign:
value = value - 512
angle = value * 8.0 / 256.0 # degree / sec
return round(angle, 3)
def cs20(msg):
"""Aircraft callsign
Args:
msg (String): 28 bytes hexadecimal message (BDS40) string
Returns:
string: callsign, max. 8 chars
"""
chars = '#ABCDEFGHIJKLMNOPQRSTUVWXYZ#####_###############0123456789######'
d = hex2bin(data(msg))
cs = ''
cs += chars[bin2int(d[8:14])]
cs += chars[bin2int(d[14:20])]
cs += chars[bin2int(d[20:26])]
cs += chars[bin2int(d[26:32])]
cs += chars[bin2int(d[32:38])]
cs += chars[bin2int(d[38:44])]
cs += chars[bin2int(d[44:50])]
cs += chars[bin2int(d[50:56])]
return cs
def is20(msg):
"""Check if a message is likely to be BDS code 2,0
Args:
msg (String): 28 bytes hexadecimal message string
Returns:
bool: True or False
"""
if allzeros(msg):
return False
d = hex2bin(data(msg))
if d[0:8] != '00100000':
return False
cs = cs20(msg)
if '#' in cs:
return False
return True
def vr53(msg):
"""Vertical rate
Args:
msg (String): 28 bytes hexadecimal message (BDS60) string
Returns:
int: vertical rate in feet/minutes
"""
d = hex2bin(data(msg))
if d[46] == '0':
return None
sign = int(d[47]) # 1 -> negative value, two's complement
value = bin2int(d[48:56])
if value == 0 or value == 255: # all zeros or all ones
return 0
value = value - 256 if sign else value
roc = value * 64 # feet/min
return roc
def vr60ins(msg):
"""Vertical rate messured by onbard equiments (IRS, AHRS)
Args:
msg (String): 28 bytes hexadecimal message (BDS60) string
Returns:
int: vertical rate in feet/minutes
"""
d = hex2bin(data(msg))
if d[45] == '0':
return None
sign = int(d[46]) # 1 -> negative value, two's complement
value = bin2int(d[47:56])
if value == 0 or value == 511: # all zeros or all ones
return 0
value = value - 512 if sign else value
roc = value * 32 # feet/min
return roc
def vr60baro(msg):
"""Vertical rate from barometric measurement, this value may be very noisy.
Args:
msg (String): 28 bytes hexadecimal message (BDS60) string
Returns:
int: vertical rate in feet/minutes
"""
d = hex2bin(data(msg))
if d[34] == '0':
return None
sign = int(d[35]) # 1 -> negative value, two's complement
value = bin2int(d[36:45])
if value == 0 or value == 511: # all zeros or all ones
return 0
value = value - 512 if sign else value
roc = value * 32 # feet/min
return roc
def is44(msg, rev=False):
"""Check if a message is likely to be BDS code 4,4
Meteorological routine air report
Args:
msg (String): 28 bytes hexadecimal message string
rev (bool): using revised version
Returns:
bool: True or False
"""
if allzeros(msg):
return False
d = hex2bin(data(msg))
if not rev:
# status bit 5, 35, 47, 50
if wrongstatus(d, 5, 6, 23):
return False
if wrongstatus(d, 35, 36, 46):
return False
if wrongstatus(d, 47, 48, 49):
return False
if wrongstatus(d, 50, 51, 56):
return False
# Bits 1-4 indicate source, values > 4 reserved and should not occur
if bin2int(d[0:4]) > 4:
return False
else:
# status bit 5, 15, 24, 36, 49
if wrongstatus(d, 5, 6, 14):
return False
if wrongstatus(d, 15, 16, 23):
return False
if wrongstatus(d, 24, 25, 35):
return False
if wrongstatus(d, 36, 37, 47):
return False
if wrongstatus(d, 49, 50, 56):
return False
# Bits 1-4 are reserved and should be zero
if bin2int(d[0:4]) != 0:
return False
vw = wind44(msg, rev=rev)
if vw is not None and vw[0] > 250:
return False
if temp44(msg):
if temp44(msg) > 60 or temp44(msg) < -80:
return False
elif temp44(msg) == 0:
return False
return True
