D Logs summary

172 MiLLennium Command Descriptions Manual

RBTA/B Satellite Broadcast Data: Raw Bits
This message contains the satellite broadcast data in raw bits before FEC (forward error correction) decoding or
any other processing. An individual message is sent for each PRN being tracked. For a given satellite, the message
number increments by one each time a new message is generated. This data matches the SBTA/B data if the
message numbers are equal. The data must be logged with the 'onnew' trigger activated to prevent loss of data.

RBTA

Structure:

RBTB

Format: Message ID = 52 Messag e byte count = 72
$RBTA week seconds prn cstatus message # # of bits
raw bits *xx [CR][LF]
Field # Field ty pe Data Description Example
1$RBTA Log header $RBTA
2week GPS week number 883
3seconds GPS seconds into the week 413908.000
4prn PRN of satellite from which data originated 115
5cstatus Channel Tracking Status 80812F14
6message # Message sequence number 119300
7# of bits Number of bits transmitted in the message. At present,
aalways equals 256 bits. 256
8raw bits 256 bits compressed into a 32 bytes. Hence, 64 hex
characters are output. 30FB30FB30FB30F878DA621
94000F18322931B9EBDBC1C
BC9324B68FBDAEBE8A
9*xx Checksum *42
10 [CR][LF] Sentence terminator [CR][LF]
Field # Data Bytes Format Units Offset
1 Sync 3 char 0
(header) Checksum 1 char 3
Message ID 4 integer 4
Message byte count 4 integer bytes 8
2Week number 4 integer weeks 12
3Seconds of week 8 double seconds 16
4PRN number 4 integer 1-999 24
5Channel Status 4 integer n/a 28
6Message # 4 integer n/a 32
7# of Bits 4 integer n/a 36
8Raw Bits 32 char n/a 40