After almost 20 flights without any issue. I got GPS-2 Error. Why? 3.5.5 | Pixhawk 2 | RTK | Auto-Mission

So yesterday i did 2 perfect flights without any issue (as always) but in the last one i got the GPS-2 Error (Error Pos Horiz Variance) in the first lane of the auto mission.

Fortunately the drone didn’t crash and finished the auto mission and didn’t showed any more error.

Any idea what could be?

I use the Here+ RTK-Base and Here+ GPS Rover.
Was very windy (25kmh/30km/h).


Thank you guys.


Please please please, post bin log, not the text one…

It seems you lost gps reception momentary, and not only at the beginning, but twice more at the end.
I would suspect an electrical error (intermittent contact, or cold joint, bad connector).


Thank you.

What type of bad connector?



I only saw one GPS ERROR in the inteire flight.

And two NO RC Receivers (its normal).

Definitely GPS-CUBE…

The last two was not long enough to cause error, but you lost all sats for a short period twice at the end.
check GPS/NSAT and GPS/HDOP.
Check your older logs as well, perhaps the problem is not entirely new.

First flight of the day:

Could it be a problem between RTK Base and RTK Rover? Using 5hz rate (base) for the first time and i think could be the problem.

Every log with 1hz and 5hz looks good, only the last one have that GPS glitch (0 sats).

So any idea?

I gravitate towards the intermittent contact failure.

How would you test it?

move cable and connectors while checking gps in mission planner.

Already did that a few times and didnt got any ‘‘gps error’’.

I’m starting to think that could be a problem related to the RTK Base -> Rover bad setup (was in an hurry - and maybe i didn’t do the correct steps in the GPS / RTK Inject tab) in that last flight.

Usually when i use RTK Base -> Rover i wait till its FIXED and i got, EVERYTIME i fly, in the HUD 13SAT max. In the GPS / RTK Inject tab i have ALOT more satellites, ofc.

In that last flight i didn’t waited for FIXED and the HUD was saying 18SAT, like i was using only the GPS in the Rover without any RTK Base.

So maybe it was a bug / issue with the Pixhawk didn’t knowing what GPS should use, if the GPS in the Rover or the RTK GPS Base.

Sorry if my english inst the best to explain correctly.

The ‘‘error’’ its in the printscreen above. It looks like the drone was using, for a few seconds, a difference reference. RTK GPS coordinates vs GPS coordinates?.

ps. green arrow is the drone direction.

@WickedShell, any ideas?

This does not explain the total loss of GPS reception. Bouncing between rtk-fix and float can cause a slight change in position, but never a lost of sats. I still think you have a HW issue.


I with you in that RTK FLOAT to RTK FIX, the bouncing is zero (already happen multiple times and zero issues).

But what i’m saying is RTK FLOAT / FIX bouncing to GPS NON-RTK (3D FIX / 3D DGPS).

Next monday i’m gonna do some tests and see what happen.

Ps. the cable between gps and pixhawk 2.1 was ‘‘loose’’ (so i tight it with some tape) - so with the speed forward (12m/s) plus wind against it, maybe could do some strange moves in the cable and could be it.