NavCom Sapphire Rev.J - Manual (Page 300)

Sapphire Technical Reference Manual Rev. J
300
2.56 NMEAALM (ASCII)
SF-3050 Sapphire SF-3040
Supported Output Rate: OFF ONCE OnChange OnTime
ONCE = output immediately once
OnChange = when GPS almanac is received
OnTime = minimum interval of 60 seconds
This output message reports orbital data (almanac) for the specified GPS satellite and is in
compliance with NMEA-0183 Standards version 3.0.

This message can now be scheduled ONTIME, with a minimum interval of 60 seconds.
When scheduled OnTime, the whole set of NMEAALM messages, which consists of
multiple messages each containing the almanac for one satellite, will be output at specified
intervals. Within the set, each almanac message will be output at one second at a time.

Refer to the section NMEA Messages Overview for general information.
The output format for this message is described in Table 142.
Table 142: ALM Message Output Format
Output Format:
$GPALM,total,message,prn,week,health,eccentricity,reftime,inclination,ascension,
axis,perigee,node,anomaly,F0clock,F1clock,*checksum
Field# Field Name Description
F1 total Total number of messages (decimal 01 to 32)
F2 message Message number (decimal 01 to 32)
F3 Prn GPS satellite PRN number (decimal 01 to 32)
F4 week Extended GPS week number (decimal 0 to 9999)
F5 health SV health (hexadecimal)
F6 eccentricity Eccentricity (hexadecimal)
F7 reftime Almanac reference time (hexadecimal)
F8 inclination Inclination angle (hexadecimal)
F9 ascension Rate of right ascension (hexadecimal)
F10 axis Root of semi-major axis (hexadecimal)
F11 perigee Argument of perigee (hexadecimal)
F12 node Longitude of ascension node (hexadecimal)
F13 anomaly Mean anomaly (hexadecimal)
F14 F0clock F0 clock parameter (hexadecimal)
F15 F1clock F1 clock parameter (hexadecimal)
F16 *CRC Checksum
Example: $GPALM,32,1,01,1423,00,35BF,7B,1F38,FD5B,A10D8B,78C23F,B7E3C6,
379706,080,001*36