ashtech HDS800, Справочное руководство

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602
Data Output
SAG: GLONASS Almanac Data
This message contains almanac data for one GLONASS
satellite.
The message is as follows:
$PASHR,SAG,<structure>
The message’s binary structure is described in the table
below.
Reminder on How
to Output SAG
Messages
Use the $PASHS,RAW command with the syntax below:
$PASHS,RAW,SAG,<port_ID>,ON,<Rate>
For more details on the $PASHS,RAW command, refer to the
Set Command Library Chapter.
As an example, the command below will output SAG
messages on port A at a rate of 15 seconds:
$PASHS,RAW,SAG,A,ON,15
Type Name Size Contents
Short prn 2 Satellite number 1-24
Short frq 2
Satellite GLONASS frequency number
[-7,…,6]
Short health 2 Satellite health 0=bad, 1=good
Float e 4 Eccentricity
Long 4
Reference day number (days in range 1 to
1461)
Float 4 Correction to inclination (semicircles)
Float w0 4
Longitude of first ascending node (semicir-
cles)
Float 4
Reference time of longitude of first node
(seconds)
w Float 4 Argument of perigee (semicircles)
Float Af0 4
Correction to mean value (43200 s) of
Draconic period
Float Af1 4 Af1=d(Af0)/dt(sec/sec)
Float 4 Satellite clock offset (seconds)
Unsigned short Checksum 2
The checksum is computed by breaking
the structure into 21 unsigned shorts, add-
ing them together, and taking the least sig-
nificant 16 bits of the result.
Total 44