Specifications

Command/Response Formats 149
Commands
$GPALM
There will be one response message for each satellite in the GPS constellation. The
response to the set or query command is in the form:
$GPALM,d1,d2,d3,d4,h5,h6,h7,h8,h9,h10,h11,h12,h13,h14,
h15*cc <enter>
Table 6.79: ALM Response Message
Parameters Description Range
d1 Total number of messages 01 -32
d2 Number of this message 01 -32
d3 Satellite PRN number 01 - 32
d4 GPS week 4 digits
h5 SV health (In ASCII Hex) 2 bytes
h6 e. Eccentricity (In ASCII Hex) 4 bytes
h7 toe. Almanac reference time (seconds. In ASCII Hex) 2 bytes
h8 Io. Inclination angle (semicircles. In ASCII Hex) 4 bytes
h9 OMEGADOT. Rate of ascension (semicircles/sec. In ASCII
Hex)
4 bytes
h10 A½. Square Root of semi-major axis (Meters & ½ In ASCII
Hex)
6 bytes
h11
ω. Argument of perigee (semicircle. In ASCII Hex)
6 bytes
h12 OMEGA0. Longitude of ascension mode (semicircle. In
ASCII Hex)
6 bytes
h13 Mo. Mean anomaly (semicircle. In ASCII Hex) 6 bytes
h14 afo. Clock parameter (seconds. In ASCII Hex) 3 bytes
h15 af1. Clock parameter (sec/sec. In ASCII Hex) 3 bytes
*cc Checksum