This has been an ongoing problem but due to its random occurrences is hard to reproduce or capture.
The aircraft was powered on and has preformed two flights captured in the log.
Sometime near the end of flight one the RTK lock was resolved but dropped back to float.
At the point it dropped back to float the RTK (F9P) GPS gained a very large offset in alt.
This is then present for the next flight.
What direction would we start looking in to find the root of this problem?
Can’t find the log.
Is your problem the fact that float is less precise than fixed regarding altitude? Or you mean that if it goes to float than it aquires an offset than it is kept even when it goes back to fixed?
Yes, probably significantly more than one meter.
The error should be removed if you are back to fix - if it is a true fix and not a false one.
I am unable to provide the log due to the nature of its specific location details.
Float is inherently less precise and I expect it to be roughly in line with non RTK GPS.
I would expect the GPS to maintain a consistent altitude when in any specific mode and maybe differ between an RTK float and an RTK fix depending on how accurate the home survey was to real world positioning.
But in this case, when the GPS is in RTK float mode it reports an altitude of 110m then latter 130m when landed. All the flight variations are observed correctly but with a 20m offset in the latter part of the log. Oddly the event that seems to correlate to this issue is a fluctuation of RTK fix type. If GPS is set to ‘use best’ it has the possibility to widley change the aircraft’s altitude if it changes between them. I believe I’ve seen the same type of problem in lat and lon as well during some previous testing which is equally concerning.