Thanks, my memo about VPS is below.
I have had VPS always ON although I have almost always flown outside (just once we dusted our living room).
A few months ago I had a Litchi mission where I foolishly set the altitude at 10 meters over our house thinking it was 2 meters above it. Miraculously the P3P hesitated and just
cleared the house's top -- maybe VPS saved me there?
I guess Phantom barometer altitude is reliable only within 10-20 meters over long distances like several hundreds of meters.
Vision Positioning System VPS uses ultrasound and image data to help the aircraft maintain its current position. With the help of it, Phantom 3 Professional can hover in place more precisely and fly indoors or in other environments where a GPS signal is not available. The main components of the it are located on the bottom of your Phantom 3 Professional; they include two ultrasonic sensors and one monocular camera.
VPS is activated automatically when the Phantom 3 Professional is turned on. It is only effective when the aircraft is at altitudes of 0.3 to 3 meters. It cannot work properly on surfaces without clear pattern variations or when operating above sound-absorbing materials. The aircraft will switch from P-mode to A-mode automatically if neither GPS nor VPS 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.
VPS may not be able to stabilize the aircraft when flying close to the ground (below 0.5 meters) at fast speeds.
Do not use other ultrasonic devices with frequency of 40 KHz when VPS is in operation.
The sonar sensor emits high frequency sounds that are only audible to some animals.
* It is OK to fly over water if you take care of following:
1. Look for the birds around
2. Your flying start direction should preferably against the wind for long distance flying
3. Have enough battery charge for safe return
4. Turn VPS off
5. You may need hand catch during landing
6. Flying over water will get you long range experience but flying near the beach and over people is not advisable.
7. Be careful, you might spot low flying helicopters too.
VPS is really designed for indoor flight so it might be best to switch it OFF outside. VPS might make for a rough/bouncy landing. P3P really resists setting down in atti mode with VPS on, to the point where it can be difficult to nail a small landing mat since the craft shoots back up to 18 inches or so when it senses the ground is too close.
Users report that:
"What I did notice in a big way was the stability hovering around and especially when a gust of wind would come by. In GPS only it would float around more and once I locked in VPS it was rock solid. Yes the landing is a little bit bouncy but I've got used to that. I will take the trade off having more stable hovering."
"If you land using auto-land or RTH right to the ground, the VPS will land gently all by itself. If you land manually, the VPS will slow it down just as it nears the ground, making it appear to bounce up a bit. I always leave it on. It has no effect over 10 feet anyway."
Turning off vps?