Specifications
Command/Response Formats 135
Commands
Where Table 6.68 on page 135 outlines the measurement structure. The checksum is
computed after the MPC header, and includes the last comma.
For details on warning flag and good/bad flag, see MBN data struct in ASCII.
Table 6.68: MPC Measurement Structure (Binary Format)
Type Size Contents
unsigned short 2 sequence tag (unit: 50 ms)
modulo 30 minutes
unsigned char 1 number of remaining struct to be sent for current epoch.
unsigned char 1 satellite PRN number.
unsigned char 1 satellite elevation angle (degree).
unsigned char 1 satellite azimuth angle (two degree increments).
unsigned char 1 channel ID (1 - 12).
C/A code data block 29 bytes
unsigned char 1 Warning flag
unsigned char 1 Indicates quality of the position measurement. (good/bad)
char 1 (set to 5 for backward compatibility)
unsigned char 1 Signal to noise of satellite observation (db.Hz)
unsigned char 1 Spare
double 8 Full carrier phase measurements in cycles.
double 8 Raw range to SV (in seconds),
i.e., receive time - raw range = transmit time
long 4
Doppler (10
-4
Hz).
long 4 bits: 0 - 23 Smooth correction (bit 0-22 = magnitude of
correction in cms, bit 23 = sign)
bits:24-31 Smooth count, unsigned. as follows:
0 = unsmoothed, 1=least smoothed, 200 = most smoothed
(29) P code on L1 block, same format as C/A code data block
(29) P code on L2 block, same format as the C/A code data block.
unsigned char 1 Checksum, a bytewise exclusive OR (XOR)
total bytes 95