ok here is my problem. I was flying my phantom 3 in an indoor swimming pool. take off fine, but the prob come when i let go of the controller, my p3 started to drift away as a wind is blowing it away. i believe this should not happen to p3 due to the sensor below it. but when i flew it elsewhere it wasfine. staying still, not drifting away. then i try to hover it on a river below 1m, still fine. so i decided to take another on the swiming pool. fly above 8m, still drifting away no hovering. and nightmare happened, my p3 hit the wall, lucky me my p3 not damage

so guys what cause it not to hover on the swimming pool water, is it because of the water
i tried calibrating the compass no luck
but i do notice when i hover it on the swimming poolfloor it is fine

I cant even think of a reason you would want to fly your rig in a swimming pool ??????????????? if your above water your supposed to turn VPS off ....

The Vision Positioning System (VPS) is the "culprit." The VPS is only good for low altitude flying and was designed with indoor flying in mind. However, it needs some kind of pattern (the sensor mechanism for the VPS is on the bottom of the Phantom) to detect and identify if it's moving or stable.

There was a cute video months ago on YouTube. The pilot hovered his Phantom above a small throw rug (very small piece of carpet). As he dragged the piece of carpet off to the side, the Phantom faithfully followed the carpet.

The manual cautions about using VPS when flying over water. Many Phantom owners turn off VPS (see SENSORS in one of the GO app menus) so it stays inactive.

Art - N4PJ
Leesburg, FL

VPS needs a clear pattern and good lighting conditions.
This is all in the specs and the manual.
It doesn't work on water.

Try an IMU calibration and calibrate the sticks on the controller.

HVAC in any big building will cause air movement.

Flying an MR in a small space will also create wind that can be come quite powerfull.

I have flown some really big hexas indoor and the vortexes created are enough to knock RC planes out of the air even 50' away. I have had this happen when our AMA club does indoor demos in schools.

My suggestion flying inside is don't expect the MR to stay in one place, just become good at atti flying. Look at the MR not the video screen. Or have a trained spotter keep an eye on the MR while you frame your shots. It is easy to drift back into something while framing a shot.

Hi ,fezanj
Please watch out your flight environment . It would be very hard to hover when flying in monotonous indoors  . By the way , the "Vision Positioning System" may find it difficult to fly above water , especially the whole blue swimming pool.

Rebel Posted at 2015-11-23 12:47
I can understand having a hard to hovering over water but why would it be difficult indoors? Isn't ...

Hi ,Rebel
Sorry to make you misunderstood . I was talking about that indoor swimming pool which is all blue .

Indoors the only thing making the aircraft stable is the VPS system, as you are unlikely to have any GPS satellites to improve the stability. But VPS does not work much above 3 Metres, and the OP may have been flying above that. He might like to chime in and say what heght he was flying at.

It clearly states that the VPS has issues over surfaces like water or moving tall grass.

Warning: The performance of your Vision Positioning System is affected by the surface over which it is flying. The ultrasonic sensors may not be able to accurately measure distances when operating above sound-absorbing materials. In addition, the camera may not function correctly in suboptimal environments. The aircraft will switch from P-mode to A-mode automatically if neither GPS nor Vision Positioning System are available. Operate the aircraft with great caution in the following situations:
Flying over monochrome surfaces (e.g. pure black, pure white, pure red, pure green).
Flying over a highly reflective surfaces.
Flying at high speeds(over 8 m/s at 2 meters or over 4 m/s at 1 meter).
Flying over water or transparent surfaces.
Flying over moving surfaces or objects.
Flying in an area where the lighting changes frequently or drastically.
Flying over extremely dark (lux < 10) or bright (lux > 100,000) surfaces.
Flying over surfaces that can absorb sound waves (e.g. thick carpet).
Flying over surfaces without clear patterns or texture.
Flying over surfaces with identical repeating patterns or textures (e.g. tiles with the same design).
Flying over inclined surfaces that will deflect sound waves away from the aircraft.

Rebel Posted at 2015-11-22 23:47
I can understand having a hard to hovering over water but why would it be difficult indoors? Isn't ...

No.....

In the hands of a skilled pilot indoor flying is possible - still not easy.
In certain places the VPS can help - but by no means should it be relied upon.

But it should not be confused with future systems which may use other means (lidar, etc.) to do more accurate positioning.

tq for all of the feedbacks