Hi all, I am a navigation software developer from Italy.

I need to understand how to read AIS data inside the "blob" contained
in VDO NMEA sentece. I have the ITU-R M.1371-1 document that should let
me understand such format. Unfortunately I really cannot understand how
to read the bits.

Someone, some times ago, posted such message:

The AIS sentences are in a strange format, encapsulated 6 bits. One
example he

'!AIVDO,1,1,,,13:r`R5P1orpG60JeHgRSj4l0000,0*56
' 0 1 2 34 5 6
'1 Total number of sentences needed to transfer the message, 1 to 9
'2 Message sentence number, 1 to 9
'3 Sequential message identifier, 0 to 9
'4 AIS channel number
'5 Encapsulateled 6-bit radio message
'6 Number of fill-bits, 0 to 5


'14eG=ch021rp4FTJdTGRRR0605q4


'VDO.Identifier : 1 000001
'Repeat indicator : 0 00
'MMSI : 316001711 010010110101011100110110101111
'VDO1.NavStatus : 0 0000
'VDO1.ROT : 0 00000000
'VDO1.SOG : 12.9 kns 0010000001
'VDO1.PosAcc : 1 1
'VDO1.Latitude : 46º 39.3182'N 1101011100000010001011010010
'VDO1.Longitude : 71º 38.2703'W
0011010101100100100010111100010100010100
'VDO1.COG : 065º 010000000000
'VDO1.Heading : 064º 110000000
'VDO1.TimeStamp : 3 sec. 000101
'VDO1.NavStatus : 0 1
'VDO1.CommStatus : 15:17 h 11001000100

I really cannot understand how he found such information inside
14eG=ch021rp4FTJdTGRRR0605q4. Please Help

Ciao
Cristiano