How does NAZA get its altitidue?

[jweaver]

I hope this isn't a stupid question, but its something I have wanted to know since I started looking at Quadcopters..

How exactly does the NAZA (or any flight controller) get its altitude data? Is it GPS? I didn't think that GPS gave very accurate altitude, especially at ground level, so I assume that it used something else.. Pressure perhaps?

Jon

[RogerD]

GPS and pressure. It has a barometer built in. Not all FCs do. Some OSDs do.