Does Vision Positioning or OPTI Mode continue to work and hold the aircraft's position (hover) should Vision Sensing mainly downward (two downward vision cameras) fail on Mavic Air? Also, is Vision Positioning subject to calibration like Vision Sensing is?

For reference, there are:
2 downward sensors (two vision sensors next to each other under colored/tinted glass)*
2 downward cameras (two vision cameras apart from each other under transparent glass)*

* Edited

The two downward IR sensors are not part of vision positioning system (VPS). These sensors is for obstacle avoidance. The VPS is based on the two downward cameras.

Generally VPS can fail if there is not enough light or if the cameras cannot recognize a pattern to use as stabilization reference for example if you fly above snow, water or other flat color surfaces.

Alex1976 Posted at 4-24 15:15
The two downward IR sensors are not part of vision positioning system (VPS). These sensors is for obstacle avoidance. The VPS is based on the two downward cameras.

Generally VPS can fail if there is not enough light or if the cameras cannot recognize a pattern to use as stabilization reference for example if you fly above snow, water or other flat color surfaces.

Alex, thank you for your reply.

My findings in Mavic Air's manual (image attached) and experience is different. The downward sensors are a part if not the major part of Vision Positioning or OPTI Mode. The downward cameras not so as in my experience OPTI mode still works with downward cameras being obstructed/failing.

It's a bit strange what you have said (and indeed what is wrote on the manual also). I have experienced a couple of times a failing of the VPS system when i have flyed indoors and with not enough light. In this case the drone has changed the flight mode from OPTI to ATTI because the downward cameras cannot recognize the floor details. Since indoors there is no GPS signal, you have automatically to manage the drone in ATTI. So how could we explain this if the downward infrared sensors is really a part of VPS system? If this would be true the drone wouldn't switch to ATTI mode.......someone tell me if i am wrong.

Alex1976 Posted at 4-29 13:43
It's a bit strange what you have said (and indeed what is wrote on the manual also). I have experienced a couple of times a failing of the VPS system when i have flyed indoors and with not enough light. In this case the drone has changed the flight mode from OPTI to ATTI because the downward cameras cannot recognize the floor details. Since indoors there is no GPS signal, you have automatically to manage the drone in ATTI. So how could we explain this if the downward infrared sensors is really a part of VPS system? If this would be true the drone wouldn't switch to ATTI mode.......someone tell me if i am wrong.

I did a small failure simulation indoors in controlled environment and found:
When both "downward vision cameras" are covered up, OPTI Mode still works.

(CAUTION: when both "downward vision sensors" are covered up, the aircraft keeps increasing altitude with/without input).