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
. 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
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
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