Here are some screenshots from program:
My plane made strange curves during flight. All curves are in the same places. After a very careful check I found an error in APM navigation code. It is now corrected in version 2.21 (In downloads section there is still the version 2.20, and there is the error.) Issue 376
First flight attempts can be quite curvy. Probably Nav_Roll P value is too big?
It seems that I must make also Nav_Pitch_Alt_Pid smaller... ?
GPS altitude (violet line) is rather slow? Air pressure altitude is probably quite ok.
Sometimes GPS altitude jumps quickly. In the last column are the values, and there is sudden 70 meters jump.
You can download this program from the address
Normally only part of the flight data is saved to log. I have changed settings so that also CTUN and NTUN are saved. This is done easily in APM Planner and there in Configuration: I changed LOG_BITMASK to 382.
PS. It was impossible to analyze flight data in the field with laptop, touchpad and very poor internet connetions. I made this program with quick and dirty method, so there may be errors.
PPS. NO, I will not make modifications or corrections to this program, but please ask Michael Oborne to make similar system to APM Planner... :-)