Symptoms
- GNSS receiver under test does not acquire satellite lock
- Slow satellite acquisition during replay
- Incomplete or unstable position solution
Possible causes
- Poor quality recorded GNSS data
- Antenna or cable connection issues
- Stored almanac data in the receiver under test
- Obstructed antenna placement during recording
Resolution
1. Verify recording conditions
During recording:
- Ensure the GNSS antenna had a clear view of the sky
- Avoid nearby obstructions such as:
- Buildings
- Trees
- Covered areas
Poor recording conditions can reduce signal quality during replay.
2. Check antenna connections
- Confirm the antenna is connected securely
- Inspect connectors for dirt or contamination
- Check cables for damage or excessive bending
If possible:
- Test using another known working antenna
3. Perform a cold start on the receiver under test
Perform a cold start after starting replay.
Stored almanac information in the receiver may cause it to search for incorrect satellites during replay.
4. Check antenna ground plane requirements
GNSS antennas typically require a suitable ground plane for optimum performance.
If recording outside a vehicle or on a non-metallic surface:
- Use an antenna with an integrated ground plane
Additional information
Objects such as buildings or trees can reduce the number and quality of tracked satellites. Atmospheric conditions such as clouds generally do not significantly affect LabSat replay performance.
Still not working?
If the receiver under test still cannot achieve satellite lock, contact Racelogic Support.