PX4 Log Files


I have questions about the log files and which source would be accurate to use as a truth source for things like lat, lng and alt.

At a quick glance we can map which logs map the parameters of interest.
AHR2 contain alt, lat, lng
Baro contain alt
POS contain alt, lat, lng
TSPI contain alt, lat, lng

It looks like there are some inconsistencies when graphing AHR2, POS and TPSI. I assume AHR2 is an AHRS. Does the pixhawk do some sort of differential GPS calculations? From experience I know that AHRS typically have multiple inputs and output a blended solution. If this is the case then then one of these log files is more accurate than the other. Unfortunately, there is limited documentation about this.

Which of these is most accurate for latitude and longitude? How about for altitude?

Lastly, what is POS? I found this old topic which states:

POS = your current fused GPS position
GPS = the last GPS measure

But it looks like that is for Arducopter but I am wondering if this holds true for PX4?