Almanacb - Novatel WAAS G-III User Manual

Data Logs
5.5.4

ALMANACB

This log contains the complete and verified collected almanac from the L1 C/A GPS signal.

If the # entries field is 0, the CRC will be output directly following the # entries field.
Output states:
Valid trigger:
Frequency:
Message ID:
Header Format:
Field Field Name
1 Header
2 System
3 Reserved
4 SVused
5 #valid
6 # entries
7 PRN
8 Week
9 Seconds
10 Ecc
Dot
11

12
o

13
M
14
o
a
15
fo
a
16
f1
17 N
18 A
19 Incl-angle
20 SV config
21 Health-prn
22 Health-alm
23 antispoof
24... Next almanac data set, offset = H + 12 + (#previous msgs x 112)
Variable 32-bit CRC
WAAS G-III Reference Receiver User Manual Rev 1
Operational
ONNEW, ONCE
When requested, when the almanac has changed
4097
G-III Log
Description
G-III log header
System the almanac pertains to
0 = GPS
Reserved
PRN of the SV the almanac is from
Number of almanacs used in validation
Number of entries to follow
PRN
Almanac reference week
Almanac reference time (s)
Eccentricity
Rate of right ascension, radians/second
Right ascension, radians
Argument of perigee, radians
Mean anomaly of reference time, radians
Clock aging parameter, seconds
Clock aging parameter, seconds/second
Corrected mean motion, radians/second
Semi-major axis, metres
Angle of inclinations relative to 0.3, radians
Satellite configuration
SV health from subframe 4 or 5
SV health from almanac
Antispoofing flag where:
0=FALSE
1=TRUE
Format # Bytes Binary Offset
H 0
Enum 2 H
Ushort 2 H+2
Ushort 2 H+4
Ushort 2 H+6
Ulong 4 H+8
Ulong 4 H+12
Ulong 4 H+16
Double 8 H+20
Double 8 H+28
Double 8 H+36
Double 8 H+44
Double 8 H+52
Double 8 H+60
Double 8 H+68
Double 8 H+76
Double 8 H+84
Double 8 H+92
Double 8 H+100
Ulong 4 H+108
Ulong 4 H+112
Ulong 4 H+116
Enum 4 H+120
H + 12 +
Hex 4
(#entries x 112)
Chapter 5
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