So the building I own is 4 stories high and I have an outdoor patio on the entire flat rooftop located 5 stories above the ground.  The rooftop area is 2,000 sq feet.

I will like to take off and land from the rooftop.  My concern is, when the P4P is turned on and sets its starting position, will the fact that it is 50 ft above ground level cause it issues?  I want to be able to control the drone from the rooftop because of the unrestricted view, but am curious to how smart the P4P is in knowing that the ground around the takeoff area is actually lower.  Thanks.

It records the height as 0 ft AGL wherever you launch it from and it doesn't have an altimeter, so it only recognizes the height above the surface it took off from, but NOT the MSL altitude.

You will be ok once you pass the rooftop yourAC will record -50 ft , just be careful rooftops of concrete buildings can play havoc with compass..

Just as piowoc73 (as well as hallmark007) says. So, you'll be able to go to a negative height if you want to fly down lower than the height of the rooftop. The quad does not know where the ground is. It knows the starting elevation, current position, and sensors can detect obstacles (like the ground).

Watch out for that rebar

Taking off from roofs causes crashes due to compass problems from the steel structure of the building, consider putting the aircraft on the lawn and then going to the roof to control it, no reason for you to be near it on take off.

piowoc73 Posted at 2017-3-5 11:44
It records the height as 0 ft AGL wherever you launch it from and it doesn't have an altimeter, so it only recognizes the height above the surface it took off from, but NOT the MSL altitude.

'It records the height as 0 ft AGL wherever you launch it from and it doesn't have an altimeter,'

Yes, it does have an altimeter, usually referred to as the barometer. I measures altitude by air pressure.

I would like to see the video. Sounds cool. Dont hand catch near the lip / edge tho

Like Mark said. If you have a concrete slab roof you are certain to have rebar and I would not recommend taking off from there. I was on my balcony concrete slab just turn it on, NOT TO FLY, and it went beezark on me!

I tried it on the ceramic floor inside the unit which is also concrete and kept telling me compass error move away.

Thanks everyone for the replies and recommendations.  I don't think it is a concrete roof.  I will take it up there just to turn it on and try and calibrate.  We'll see what it says.  Thanks.

Steevr Posted at 2017-3-5 16:39
Thanks everyone for the replies and recommendations.  I don't think it is a concrete roof.  I will take it up there just to turn it on and try and calibrate.  We'll see what it says.  Thanks.

do NOT calibrate up there!

once you compass is set somewhere in clear and open area leave it alone.

The LAST thing you want to do is calibrate near that rebar etc...

if you do fly from the patio use plastic or wood to elevate the quad well away from any rebar in concrete .
etc.

Good luck and have fun flying!

Nigel_ Posted at 2017-3-5 13:13
Taking off from roofs causes crashes due to compass problems from the steel structure of the building, consider putting the aircraft on the lawn and then going to the roof to control it, no reason for you to be near it on take off.

Not necessarily true.   If you do not get compass issues before flight then isn't an issue.

Dronesmeg flies from his rooftop and it's where I first flew his drone from.

Landing also was not an issue.

blackcrusader Posted at 2017-3-5 17:31
Not necessarily true.   If you do not get compass issues before flight then isn't an issue.

Dronesmeg flies from his rooftop and it's where I first flew his drone from.

Yes, it is true. There have been many cases reported here where someone took off from a concrete pad and then lost control of their aircraft once they were in the air. It is not a case of opinion, it is a reality. And you will not always get a compass warning if you do this because the aircraft fires up on the spot and thinks the compass is reading normally, once in the air it finds the readings are bad.