u-blox ZED-F9P - Page 123

u-blox ZED-F9P Interface Description - Manual
Advance Information
5.12.6.2 UBX-MGA-GPS-ALM
Message
UBX-MGA-GPS-ALM
Description
GPS Almanac Assistance
Firmware
Supported on:
• u-blox 9 with protocol version 27
Type
Input
Comment
This message allows the delivery of GPS almanac assistance to a receiver. See the
description of AssistNow Online for details.
Header Class ID Length (Bytes) Payload Checksum
Message Structure
0xB5 0x62 0x13 0x00 36
see below
CK_A CK_B
Payload Contents:
Byte Offset Number
Format
Scaling Name Unit Description
0 U1 - type - Message type (0x02 for this type)
1 U1 - version - Message version (0x00 for this version)
2 U1 - svId - GPS Satellite identifier (see Satellite Numbering)
3 U1 - svHealth - SV health information
4 U2 2^-21 e - Eccentricity
6 U1 - almWNa week Reference week number of almanac (the 8 bit
WNa field)
7 U1 2^12 toa s Reference time of almanac
8 I2 2^-19 deltaI semi-
circles
Delta inclination angle at reference time
10 I2 2^-38 omegaDot semi-
circles/s
Rate of right ascension
12 U4 2^-11 sqrtA m^0.5 Square root of the semi-major axis
16 I4 2^-23 omega0 semi-
circles
Longitude of ascending node of orbit plane
20 I4 2^-23 omega semi-
circles
Argument of perigee
24 I4 2^-23 m0 semi-
circles
Mean anomaly at reference time
28 I2 2^-20 af0 s Time polynomial coefficient 0 (8 MSBs)
30 I2 2^-38 af1 s/s Time polynomial coefficient 1
32 U1[4] - reserved1 - Reserved
UBX-18010854 - R04 Advance Information Page 115 of 259