Sal: Gps Almanac Data - Magellan ProFlex 500 Reference Manual

SAL: GPS Almanac Data

Where
Parameter
d1 SBAS SV ID number
Time tag: hhmmss.hh
The SBA,DAT message contains the time tag of
m2
the beginning of WAAS message transmission
(WAAS message transmission time is 1 second)
d3 RTCA message ID
Error flags (in HEX): bit0-preamble error, bit1-par-
d4
ity error
RTCA message: 250 bit in 63 HEX numbers. The
data lie from left to right and from high-order to
s5
low-order bits. The two low-order bits in the 63rd
number are not used.
*cc Checksum
This message contains almanac data for one GPS satellite.
The message is as follows:
$PASHR,SAL,<structure>
The message's binary structure is described in the table
below.
Type Name Size
Short prn 2
Short health 2
Float e 4
Long toe 4
Float i0 4
Float w dot 4
Double A1/2 8
Double w0 8
Double w 8
Double M0 8
Float Af0 4
Float Af1 4
Short wna 2
Short wn 2
Long 4
Description
Contents
Satellite PRN number minus 1 (0-31)
Satellite health
Eccentricity
Reference time for orbit (sec)
Inclination angle at reference time (semi-cir-
cles)
Rate of right ascension (semi-circles/sec)
Square root of semi-major axis (meters1/2)
Longitude of ascending node (semicircles)
Argument of perigee (semicircles)
Mean anomaly at reference time (semi-circle)
Clock correction (sec)
Clock correction (sec/sec)
Almanac week number
GPS week number
Seconds of GPS week
Data Output
Range
33-51
000000.00-
235959.99
0-63
0-2
*00-*FF
283