Landing protection status returned by the downward vision sensor.
The aircraft is not executing auto-landing or the downward vision sensor has not started to analyze the ground yet.
The downward vision sensor is analyzing the ground at the landing zone.
The downward vision sensor's analysis failed. Either the auto-landing can be attempted again, or the user needs to land the aircraft manually.
The ground is flat and the aircraft is safe to land automatically.
Landing area is not flat enough to be considered safe for landing. The aircraft should be moved to an area that is more flat and an auto-land should be attempted again or the user should land the aircraft manually.