GPSTime Message accuracy (not precision)


I am using the “CAM” message in the pixhawk log in a hot-shoe scheme.

I know the GPSTime message resolution/precision is only 100msec, which is pretty course.

However - I am interested in the accuracy component. How accurate is the GPSTime message? Can it be off by 100msec at times ?


It ranges between 0.06 and 0.16 sec for us, but also depends on FCC platform and GNSS receiver.

It would be good to have PPS feedback from GNSS receiver to timestamp CPU time.

Tnx for the quick reply @vbnhu.

Can you elaborate on how you came about these 0.06-0.16s numbers?


Hi @gast ! I am comparing raw GPS velocity / change in velocity (post processed from the GPS rinex log) vs. the logged yaw angle, logged yaw rate coming from APM data. In case you make a cross correlation between them 0.06-0.16s gives you the best correlation, but the number varies based on the FCC onbord.

Tnx @vbnhu - appreciate your response