Novatel 15a Car Satellite TV System User Manual


 
Data Logs Chapter 6
EuroPak-15a Receiver User Manual Rev 5 75
6.3.2 ALMANAC Decoded Almanac
This log contains the decoded almanac parameters for the frequency specified in the POSITIONTYPE
command, see Page 61. Multiple messages are transmitted, one for each SV almanac collected. For more
information on Almanac data, refer to the GPS SPS Signal Specification. A list of standards and references
with contact information can be found in the GPS+ Reference Manual available on our website at http://
www.novatel.com/support/docupdates.htm.
Log Type: Asynch Message ID: 73
Field
Field
Name
Description Format
Binary
Bytes
Binary
Offset
1 header
This field contains the message header, in ASCII or Binary format.
See Section 4.3 on Page 35.
H 0
2 #msg The number of satellite PRN almanac data sets to follow. Long 4 H
3 PRN Satellite PRN number for current message, dimensionless ULong 4 H+4
4 week Almanac reference week (GPS week number) ULong 4 H+8
5 seconds Almanac reference time, seconds into the week Double 8 H+12
6 ecc Eccentricity, dimensionless Double 8 H+20
7 Rate of right ascension, radians/second Double 8 H+28
8 Right ascension, radians Double 8 H+36
9 Argument of perigee, radians Double 8 H+44
10 M
o
Mean anomaly of reference time, radians Double 8 H+52
11
a
fo
Clock aging parameter, seconds Double 8 H+60
12
a
f1
Clock aging parameter, seconds/second Double 8 H+68
13 N Corrected mean motion, radians/second Double 8 H+76
14 A Semi-major axis, meters Double 8 H+84
15 incl-angle Angle of inclination relative to 0.3 π, radians Double 8 H+92
16 SV config Satellite configuration ULong 4 H+100
17 health-prn SV health from subframe 4 or 5 ULong 4 H+104
18 health-alm SV health from almanac ULong 4 H+108
19 antispoof Anti-spoofing flag, see Table 17 on Page 46 Enum 4 H+112
20... Next almanac data set, offset = H + 4 + (# previous msg x 112)
21 32-bit CRC (ASCII and Binary only) Hex 4
H + 4 +
(112 x
#msg)
ω
°
ω
0
ω