Are the downward sensors right near the gimbal working in low light ? i had a rough landing yesterday and lost plastic leg cover on impact.

Yes, they are to the rear of the gimbal on the main body and should work with minimum light. Did you get a wrning telling you the sensors were not working do to low light?

Well, it depends on how low the light is... and also in the kind of surface they are pointing at (color, texture,  tiling etc. ) -Where you in Auto landing?

Antonio76 Posted at 2017-7-21 08:27
Well, it depends on how low the light is... and also in the kind of surface they are pointing at (color, texture,  tiling etc. ) -Where you in Auto lending?

No i was just ten feet high and pulled the stick all the way down to test if the sensors would detect the grass and slow down like when it returns home by itself. It just banged on the ground and up loosing one of the antenna s plastic cover that snaps on the side of the leg. It was about 15 min before complete darkness.  But i thought the bottom sensors were working with some sort of ultra sounds no mater daytime or night !?

racer888 Posted at 2017-7-21 04:28
Yes, they are to the rear of the gimbal on the main body and should work with minimum light. Did you get a wrning telling you the sensors were not working do to low light?

No i did not get any warnings neither got warnings telling me that all obstacle would not work due to low light (15 mins before dark in my case).

coco60 Posted at 2017-7-21 09:50
No i was just ten feet high and pulled the stick all the way down to test if the sensors would detect the grass and slow down like when it returns home by itself. It just banged on the ground and up loosing one of the antenna s plastic cover that snaps on the side of the leg. It was about 15 min before complete darkness.  But i thought the bottom sensors were working with some sort of ultra sounds no mater daytime or night !?

well, 15 minutes before complete darkness seems pretty dark to me. Anyway, the way you were flying says that autolanding was off, so the vision positioning system was simply working at keeping the aircraft hovering **if there was not other vertical input from the left stick**. But by pulling the stick all the way down you ordered the aircraft to descend at full speed without also telling it to use Landing Protection, which would have prevented the hard touch down...

FWIW: If I am going to fly at night, I usually have either a flashlight with me or a LED lantern that I put on the ground.  Lighting up the landing area really makes a difference when flying at night.
Also, for what its worth, keep in mind that official sunset is the legal stop time for you to fly.  If you were flying until all the light was gone, you were flying illegally.  We all do it to varying degrees, but just know that the official sunset (look on any weather site to find the official sunset) is your cutoff time.  After that you start to risk getting a fine.

You CAN fly for 30 minutes past official sunset (in what is called "Civil Twilight") but you need an inexpensive obstacle avoidance light stuck to the top of your drone.  The light is required to have a minimum 3 mile visibility (and no, the lights on the drone motors don't qualify).

Mabou2 Posted at 2017-7-21 12:12
FWIW: If I am going to fly at night, I usually have either a flashlight with me or a LED lantern that I put on the ground.  Lighting up the landing area really makes a difference when flying at night.
Also, for what its worth, keep in mind that official sunset is the legal stop time for you to fly.  If you were flying until all the light was gone, you were flying illegally.  We all do it to varying degrees, but just know that the official sunset (look on any weather site to find the official sunset) is your cutoff time.  After that you start to risk getting a fine.

He was flying illegally only if he is a commercial 107 pilot without a "day time waiver". Hobbyists are not restricted to the civil twilight rules we commercial pilots are, go figure??

coco60 Posted at 2017-7-21 09:50
No i was just ten feet high and pulled the stick all the way down to test if the sensors would detect the grass and slow down like when it returns home by itself. It just banged on the ground and up loosing one of the antenna s plastic cover that snaps on the side of the leg. It was about 15 min before complete darkness.  But i thought the bottom sensors were working with some sort of ultra sounds no mater daytime or night !?

The height above ground is measured using the ultrasonic sensors. The horizontal position is set by the cameras. The VPS will disable if not enough light, you will get notification on screen and VPS icon will turn red. It may also have been disabled in DJI Go 4. I believe the ultrasonic sensors will operate up to 10m above surface level.

Try using air to clean the dust or dirt fixed mine

Interesting issue ... I wonder if front sensors will stop the drone when flying full throttle toward brick wall in low light ... Would you test this for us, please? Don't forged to turn recording on ...

Dobmatt Posted at 2017-7-29 12:36
Interesting issue ... I wonder if front sensors will stop the drone when flying full throttle toward brick wall in low light ... Would you test this for us, please? Don't forged to turn recording on ...

You are evil.

Dobmatt Posted at 2017-7-29 12:36
Interesting issue ... I wonder if front sensors will stop the drone when flying full throttle toward brick wall in low light ... Would you test this for us, please? Don't forged to turn recording on ...

I'm sure that's been tried, tested, and questioned by a few in the past 18 months

Geebax Posted at 2017-7-29 14:20
You are evil.

OP seems to be brave, curious person, learning the features of a new toy by experimentation rather than reading (see post #4). I must confess, however, that sometimes I can't control nasty habit of being sarcastic ... My apologies.

Dobmatt Posted at 2017-7-29 18:43
OP seems to be brave, curious person, learning the features of a new toy by experimentation rather than reading (see post #4). I must confess, however, that sometimes I can't control nasty habit of being sarcastic  ... My apologies.

No need to apologise, you do it so well.

racer888 Posted at 2017-7-22 05:02
He was flying illegally only if he is a commercial 107 pilot without a "day time waiver". Hobbyists are not restricted to the civil twilight rules we commercial pilots are, go figure??

How can that be when we 107 commercial pilots can fly hobbyist as well. As long as we are not working.

I've been getting the downward sensor failure warning almost daily on my P4P, sometimes 20 feet in the air, sometimes 399 feet and anywhere in between. I've recalibrated the sensors at least 5 times in the last month. Test fly afterward and fine fora couple flights then bam...I've tried four different peripherals, iPhone 6s, iPhone 7, iPad 2 Air and iPad Pro with same results. I've refreshed the firmware at least twice and removed and reinstalled the app on the iPad 2 Air twice since that is the device I use with that P4P for my job as a photojournalist. Drone was purchased last Oct, used sparingly through the winter in CT, no crashes or hard landings (use hand catch). I have an older P4P that is my personal drone for side biz and pleasure with out any issues going on a year and a half. Very frustrated with the failures. I turn off half the sensors now just so I don't get the warning since nothing seems to fix it...

Samara1 Posted at 2018-7-8 18:24
I've been getting the downward sensor failure warning almost daily on my P4P, sometimes 20 feet in the air, sometimes 399 feet and anywhere in between. I've recalibrated the sensors at least 5 times in the last month. Test fly afterward and fine fora couple flights then bam...I've tried four different peripherals, iPhone 6s, iPhone 7, iPad 2 Air and iPad Pro with same results. I've refreshed the firmware at least twice and removed and reinstalled the app on the iPad 2 Air twice since that is the device I use with that P4P for my job as a photojournalist. Drone was purchased last Oct, used sparingly through the winter in CT, no crashes or hard landings (use hand catch). I have an older P4P that is my personal drone for side biz and pleasure with out any issues going on a year and a half. Very frustrated with the failures. I turn off half the sensors now just so I don't get the warning since nothing seems to fix it...

Look out for the thread on ultrasonic sensor error and reply to one of DJI Susans latest post, there is a beta out that might solve your issue.

Hello dears!
my friend have a ph 3 pro. and we are beginner in phantom , and we dont know it is error or not that when he take off the hight feedback value is ok, but
when he fly 10-20-50-500m in any direction (only forexample horizontally) the high feedback value is go fals. it is sensor error? or it is normal operation? (we have near all gps signal )
im a spark user, but i think spark has more intelligent and more precise sensors or not?
so it is normal for phantom 3 pro? or i need to go serviceÍ to repair sonic sensor?

(we made all recalibrating lot times)