Trimble GPS Troubleshooting and FAQ

Owned by jr_mateo
Last updated: Nov 02, 2021
1 min read

1. NaviPac Instrument monitor shows some empty cycles for a GPS.

a. Degraded satellite signal.

b. Depending on the satellite constellation/s being used, the GPS is sending a different NMEA prefix that expected. For example, the $GP prefix (for GPS-US signal) is specified in the NaviPac instrument property, but the receiver is sending $GN (Global Navigation satellite System signal).

 

2. The GPS receiver is tracking several satellites from the GNSS constellations, but it is only using one constellation for the position solution (e.g. GPS)

"Satellites may not be used if no ephemeris available, measurements do not meet the receiver's quality requirements, or differential correction data is not available" (https://www.trimble.com/EC_ReceiverHelp/positionInfo.html)

 

3.