190-00885-07
GPS 17x HVS Technical Specifications
Rev. A
Page 22
Satellite Data Record
The satellite data has a record ID of 0x72 with 84 (0x54) data bytes. The data bytes contain data for 12 satellites as
described below.
typedef struct
{
uint8
svid;
//space vehicle identification (1–32 and 33–64 for
SBAS(WAAS/EGNOS/MSAS) )
uint16
snr;
//signal-to-noise ratio
uint8
elev; //satellite elevation in degrees
uint16
azmth;
//satellite azimuth in degrees
uint8
status; //status bit-field
}
cpo_sat_data;
The status bit field represents a set of booleans described below:
Bit
Meaning when bit is one (1)
0
The unit has ephemeris data for the specified satellite.
1
The unit has a differential correction for the specified satellite.
2
The unit is using this satellite in the solution.
This pattern is repeated for 12 satellites for a total of 12 X 7 bytes = 84 (0x54) bytes.
The RS-232 Packet for the Satellite Record looks like:
- 0x10
(DLE is first byte)
- 0x72
(Record ID – single byte)
- 0x54
(Number of data bytes – single byte)
- 12 cpo_sat_data records
- 0x##
(2’s complement of the arithmetic sum of the bytes between the delimiters)
-
0x10
(DLE)
-
0x03
(ETX
is
last
byte)
