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mux0183/lib/aisMsg.py
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aisMsg.py
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#!/usr/bin/python
from bitBuf import bitBuf
from nmea import NMEAaddChecksum
#
# AIS message
#
encodingTable = "0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVW`abcdefghijklmnopqrstuvw"
class AISmsg :
def __init__(self) :
self.type = 0
self.repeat = 0
self.mmsi = 0
self.bb = bitBuf()
self.aisframe = ''
self.padding = 0
def toAscii(self) :
out = ''
if self.bb.bit == 0 :
self.bb.buff.pop() # delete last element
for c in self.bb.buff :
if c < 64 :
out += encodingTable[c]
return out
# Encapsulate AIS frame in multiple NMEA frames
def EncapInAIVDM(self) :
multi = []
count = (len(self.aisframe)-1) / 60 # MAX_AIS=60
count += 1
segment = 0
for i in range(0, count) :
subframe = self.aisframe[segment:segment+60]
aivdm = "!AIVDM,"+str(count)+","+str(i+1)+",,A,"+subframe
segment += 60
if i != count-1 :
aivdm += ",0"
else :
aivdm += ","+str(self.padding)
aivdm = NMEAaddChecksum(aivdm)
multi.append(aivdm)
return multi
class AISmsg1(AISmsg) :
UNDERWAY = 0
ANCHOR = 1
NOT_UNDER_COMMAND = 2
RESTRICTED_MANOEUVRABILITY = 3
CONSTRAINED_DRAUGHT = 4
MOORED = 5
AGROUND = 6
FISHING = 7
SAILING = 8
SART_ACTIVE = 14
SART_TEST = 15
HDG_NOT_AVAILABLE = 511
SPECIAL_MANOEUVRE_NOT_AVAIL = 0
SPECIAL_MANOEUVRE_NOT_ENGAGED = 1
SPECIAL_MANOEUVRE_ENGAGED = 2
def __init__(self) :
AISmsg.__init__(self)
self.type = 1
self.repeat = 0
self.mmsi = 0
self.navStatus = AISmsg1.UNDERWAY
self.rot = 0.0
self.sog = 0.0
self.accuracy = 0
self.lon = 0.0
self.lat = 0.0
self.cog = 0.0
self.hdg = AISmsg1.HDG_NOT_AVAILABLE
self.timeStamp = 0
self.specialManoeuvre = AISmsg1.SPECIAL_MANOEUVRE_NOT_AVAIL
self.RAIM = 0
self.state = 0
def encode(self) :
self.bb = bitBuf()
self.aisframe = ''
self.padding = 0
self.bb.WriteByte (self.type, 6)
self.bb.WriteByte (self.repeat, 2)
self.bb.WriteByte (self.mmsi, 30)
self.bb.WriteByte (self.navStatus, 4)
self.bb.WriteByte (128, 8)
self.bb.WriteInteger (int(self.sog * 10), 10)
self.bb.WriteBit (self.accuracy)
lon = int((self.lon * 600000) + 0.5)
if self.lon < 0 :
lon = (lon ^ 0x0fffffff) + 1 # 2-complement
self.bb.WriteInteger (lon, 28)
lat = int((self.lat * 600000) + 0.5)
if self.lat < 0 :
lat = (lat ^ 0x0fffffff) + 1 # 2-complement
self.bb.WriteInteger (lat, 27)
self.bb.WriteInteger (int(self.cog * 10), 12)
self.bb.WriteInteger (int(self.hdg), 9)
self.bb.WriteByte (self.timeStamp, 6)
self.bb.WriteByte (self.specialManoeuvre, 2)
self.bb.WriteByte (0, 3) # spare
self.bb.WriteBit (self.RAIM)
self.bb.WriteInteger (self.state, 19)
#self.bb.info()
self.aisframe = self.toAscii()
self.padding = self.bb.Padding()
class AISmsg5(AISmsg) :
VERSION_M1371_1 = 0
VERSION_M1371_3 = 1
PILOT_VESSEL = 50
SAR_VESSEL = 51
TUG = 52
PORT_TENDER = 53
DEVICE_UNDEFINED = 0
DEVICE_GPS = 1
DEVICE_GLONASS = 2
DEVICE_LORANC = 4
DEVICE_GALILEO = 8
def __init__(self) :
AISmsg.__init__(self)
self.type = 5
self.version = self.VERSION_M1371_1
self.imo = 0
self.callSign = ''
self.name = ''
self.shipType = 0
self.to_bow = 0
self.to_stern = 0
self.to_port = 0
self.to_starboard = 0
self.deviceType = self.DEVICE_UNDEFINED
self.eta = 0
self.draught = 0
self.destination = ''
self.dte = 0
def encode(self) :
self.bb = bitBuf()
self.aisframe = ''
self.padding = 0
self.bb.WriteByte (self.type, 6)
self.bb.WriteByte (self.repeat, 2)
self.bb.WriteByte (self.mmsi, 30)
self.bb.WriteByte (self.version, 2)
self.bb.WriteInteger (self.imo, 30)
self.bb.WriteString (self.callSign, 7)
self.bb.WriteString (self.name, 20)
self.bb.WriteByte (self.shipType, 8)
self.bb.WriteInteger (self.to_bow, 9)
self.bb.WriteInteger (self.to_stern, 9)
self.bb.WriteByte (self.to_port, 6)
self.bb.WriteByte (self.to_starboard, 6)
self.bb.WriteByte (self.deviceType, 4)
self.bb.WriteInteger (self.eta, 20)
self.bb.WriteByte (self.draught * 10, 8)
self.bb.WriteString (self.destination, 20)
self.bb.WriteBit (self.dte)
self.bb.WriteBit (0) # spare
self.aisframe = self.toAscii()
self.padding = self.bb.Padding()
if __name__ == '__main__':
obj = AISmsg5()
obj.mmsi = 205344990
obj.callSign = 'ATC'
obj.name = 'PETIT BAIGNEUR'
obj.destination = 'MARSEILLE'
obj.to_bow = 50;
obj.to_stern = 20;
obj.to_port = 10;
obj.to_starboard = 10;
obj.draught = 10;
obj.encode()
multi = obj.EncapInAIVDM()
for aivdm in multi :
print aivdm
obj = AISmsg1()
obj.mmsi = 205344990
obj.navStatus = AISmsg1.UNDERWAY;
obj.sog = 20;
obj.accuracy = 1;
obj.lat = 43.01666;
obj.lon = 6.0;
obj.cog = 110.7;
obj.hdg = AISmsg1.HDG_NOT_AVAILABLE;
obj.timeStamp = 40;
obj.specialManoeuvre = AISmsg1.SPECIAL_MANOEUVRE_NOT_AVAIL;
obj.RAIM = 1;
obj.state = 0;
obj.encode()
multi = obj.EncapInAIVDM()
for aivdm in multi :
print aivdm
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