Could I change main factor to set altitude?

Continuing the discussion from Pixracer copter make error about altitude:

I have experience that barometer make some error. I know that barometer is good to set altitude. But sometimes the sensor has broken or breakdown.

As I know, to set altitude use barometer. But I would like to test with GPS’ Z-axis.
Could I change it? or some change firmware’s code?

the log looks like your baro actually has some problem but as you can see in log ‘estimated altitude’ is similar to GPS altitude which means when fusing data GPS value takes far more higher gain on it so if your using GPS enabled mode
you don’t have to change things

OK, I understand what you said. Thanks for your answer. As you said GPS values takes far more higher gain on it. And I could see the drone more higher than what I set. Therefore I guess that the GPS doesn’t have error. If I understand exactly, barometer has error and GPS doesn’t. If possible, I don’t want to change FC and want to fly just using GPS. So I want to review whether it is possible.

in your log your altitude estimation exactly follows to your set point altitude
how do you know it flew higher than you set?

Because I fly multiple drones with same altitude. But just that drone fly more higher than others. As fat as I see, the error drone more higher 20m than others.