I want to know what flight state means and if it is possible to execute a mission.

[masayuki-kobayashi1]

@AutelSDK
Check FlyState before flying.
There seem to be five FlyStates: GPS, ATTI, IOC, STARPOINT, and UNKNOWN. The problem is that I don't know what they mean.
Also, I don't know which FlyState can or cannot execute a mission.
Please help me know.