ashtech ZY-12 Information Supplement page 97

satellite for which the receiver has collected almanac data. Table 4.10 below
outlines the contents of the SALM message.
The structure of the SALM message is shown below:
$PASHR,ALM,<Almanac Data + Checksum>
Type
short
short
float
long
float
float
double
double
double
double
float
float
short
short
long
unsigned short
Total bytes70
Serial Port Output
Table 4.10. ALM Message Structure
Size
2 Satellite PRN -1
2 Health. see ICD - 200 for description
4 e. Eccentricity
4 toe. Reference time for orbit (sec)
4 I0. Inclination angle at reference time (semi-circles).
4 OMEGADOT. Rate of right Asc. (semi-circles per sec).
8 (A)1/2. Square root of semi-major axis (meters 1/2).
8 (OMEGA)0. Lon of Asc. node (semi-circles).
ω
8
. Argument of Perigee (semi-circles)
8 M0. Mean anomaly at reference time (semi-circle).
4 af0. sec
4 af1. sec/sec.
2 almanac week number
2 GPS week number
4 Seconds of GPS week
2 Word checksum
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