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
1header 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
3PRN Satellite PRN number for current message, dimensionless ULong 4H+4
4week Almanac reference week (GPS week number) ULong 4H+8
5seconds Almanac reference time, seconds into the week Double 8H+12
6ecc Eccentricity, dimensionless Double 8H+20
7Rate of right ascension, radians/second Double 8H+28
8Right ascension, radians Double 8H+36
9Argument of perigee, radians Double 8H+44
10 MoMean anomaly of reference time, radians Double 8H+52
11 afo Clock aging parameter, seconds Double 8H+60
12 af1 Clock aging parameter, seconds/second Double 8H+68
13 N Corrected mean motion, radians/second Double 8H+76
14 A Semi-major axis, meters Double 8H+84
15 incl-angle Angle of inclination relative to 0.3 π, radians Double 8H+92
16 SV config Satellite configuration ULong 4H+100
17 health-prn SV health from subframe 4 or 5 ULong 4H+104
18 health-alm SV health from almanac ULong 4H+108
19 antispoof Anti-spoofing flag, see Table17 on Page 46 Enum 4H+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
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