Unhealthy GPS Signal - good sat count/HDOP

I am consistently having issues with my rover with an unhealthy GPS signal error on the mission planner HUD. This is preventing the move from manual to auto mode. I am seeing a sat count of 15+ and a HDOP of 0.8. How can I go about better diagnosing this error message? I am getting the same error with a HERE3+ unit and Holybro micro M9N unit. I’ve tried messing around with constellations but to no avail.

Any help would be much appreacited.

For the m9n, it shouldn’t have such a bad number of satellites, at least 25+ satellites, you need to place it outdoors with a good view of the sky.

It could be caused by:

  • interference - poor power supply, telemetry radio too close
  • multipathing due to nearby structures
  • poor compass calibration

Set GPS_GNSS_MODE to use just GPS and GLONASS, only add SBAS if you are in USA.
Limiting the constellations usually helps with more than just the update rate.

If you do get mobile with a good GPS 3D Fix do a bunch of turns and circles. Supply a .bin log file and we can run it through Magfit to sort out the compass calibration.

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