Sensors on the bottom of my Drone do what?

[welbeck]

2 are ultrasonic i.e. tell the distance from the floor using sound but what are the other 2 for? They're the same as the forward facing ones that stop me running into things and have a couple of times but what do the ones on the bottom actually do? If I'm flying along on the flat then reach an incline will they warn me that I'm going to beach my craft or even stop me. I can't afford to fix if if ever I break it, it was bought as a present before anyone says I shouldn't have bought it. Just not sure what protection I've got. Can someone please enlighten me

 

[Deleted member 62848]

2 are ultrasonic i.e. tell the distance from the floor using sound but what are the other 2 for? They're the same as the forward facing ones that stop me running into things and have a couple of times but what do the ones on the bottom actually do? If I'm flying along on the flat then reach an incline will they warn me that I'm going to beach my craft or even stop me. I can't afford to fix if if ever I break it, it was bought as a present before anyone says I shouldn't have bought it. Just not sure what protection I've got. Can someone please enlighten me

Vps will allow drone to establish a height value without gps,ultra sonic mechanical clicking noise ,unsure but think bottom cameras called on ocular or monocular,I think front called monocular cam because it scanning ahead and bottom scans down which why sometimes unsteady hover occurs over some patterns on ground at low level,,bottom cams will not stop you hitting something unlike how front works (obstical avoidence),