Launching from on top of a high rise building

[Reuben]

Had to launch from a high rise roof top for a job in the CBD. Lots of buildings nearby and constantly got a compass calibration error. Did the usual circles horizontal and vertical a number of times in each corner of the roof as far away from metal railing etc. Finally got it calibrated in one spot. Then before takeoff checked the radio signal strength and it wasn’t good on the cendence controller with a patch antennae at 2.8ghz. Switched to 5.4ghz and it was worse. On each frequency was getting mainly red bars on all but one column. I took off at 2.8ghz to hover for about 30 secs only a metre off the ground and received a warning on the signal strength. Landed immediately and pulled the pin on the roof launch. Ended up getting a ground permit and did the job from the ground which was difficult given the location but felt like the safer option. Whilst in the air I was able to get close to where I took off and half circle the building all without any signal issues. Any advice on what I could do as the ground permit costed $500. Taking off from the building costs $0.

I’m assuming the interference was coming from neighboring buildings, mobile towers, etc but not sure why I had better luck from the ground at a much further distance (around 70m) than only metres from it on the rooftop.

Thanks in advance.

 

[sdunwell]

Regarding the compass calibration part of your post - (1) calibrate at some nearby open space beforehand, then (2) put drone on a non-ferrous table or ladder several feet above the roof, or hand-held then (3) turn it on. It will probably start up with a clean compass. Regarding signal - sounds like RF interference, no advice (alas).

 

[hhung516]

Can you take off with you standing on top of the building and drone on the ground?

 

[Helicek Ahmet]

I experience similar interference problems on roof tops in the city (in Istanbul). Both my Inspire1 Pro and P4 Pro drones. I prefer to be on the roof. On a roof top I have a very clear view of the drone and I don't have to worry about getting building blocks between me and my drone. As "sdunwell" suggested it is usually possible to find a spot on the roof with minimum wifi and ferrous metal interference. It usually the ferrous web inside roof casting structure causing compass error.

 

[Helicek Ahmet]

Can you take off with you standing on top of the building and drone on the ground?

I would feel very uncomfortable doing that on the roof of a 22 storey building. Can not see the bit of land where drone takes off

 

[Reuben]

I experience similar interference problems on roof tops in the city (in Istanbul). Both my Inspire1 Pro and P4 Pro drones. I prefer to be on the roof. On a roof top I have a very clear view of the drone and I don't have to worry about getting building blocks between me and my drone. As "sdunwell" suggested it is usually possible to find a spot on the roof with minimum wifi and ferrous metal interference. It usually the ferrous web inside roof casting structure causing compass error.

Thanks for sharing your experience. I’m guessing once I flew out from the building it would’ve been fine, but I just wasn’t confident with the warnings going off. Even though the flight with a ground launch went well I’m not sure if I’d still get RF interference with the remote by being up amongst all the metal and other signals present.

 

[Reuben]

Can you take off with you standing on top of the building and drone on the ground?

Wouldn’t be able to see it well enough to avoid any obstacles. There are a heap of trees around the building at ground level. Ground launch was still tricky but easy enough by just taking my time getting it past the tree canopy. This is why I was hoping to take off from the roof. Would’ve been so much more efficient

 

[Gary Patterson]

I'm a commercial roof consultant that uses drones to assist in evaluation of roofs. I've experienced similar issues when flying my Inspire 1. Most commercial buildings rely on a metal roof deck under the entire roof area to provide support for roofing materials. This layer of metal may be the reason for compass and RF interference. Any thoughts?

 

[Reuben]

I'm a commercial roof consultant that uses drones to assist in evaluation of roofs. I've experienced similar issues when flying my Inspire 1. Most commercial buildings rely on a metal roof deck under the entire roof area to provide support for roofing materials. This layer of metal may be the reason for compass and RF interference. Any thoughts?

Thanks for the info. Yes it seems like the best move is to calibrate elsewhere before a rooftop launch. Just not sure if that metal would still interfere with the remote whilst on the roof

 

[Gary Patterson]

Thanks for the info. Yes it seems like the best move is to calibrate elsewhere before a rooftop launch. Just not sure if that metal would still interfere with the remote whilst on the roof

It has been my experience that a rooftop launch does not resolve this issue even if you calibrate elsewhere, although once you're airborne everything seems to work properly as long as you maintain line of sight from the RC. It might be worth while to get on top of the roof with your RC and then launch from the ground. Of course, you should have somebody on the ground monitoring your flight from that location. I would recommend landing on the ground and not the roof.

 

[Reuben]

It has been my experience that a rooftop launch does not resolve this issue even if you calibrate elsewhere, although once you're airborne everything seems to work properly as long as you maintain line of sight from the RC. It might be worth while to get on top of the roof with your RC and then launch from the ground. Of course, you should have somebody on the ground monitoring your flight from that location. I would recommend landing on the ground and not the roof.

Yeah I think I’ll just go from the ground in future. Too stressful up there with the warnings and a heap of obstacles to hit if the drone loses connection and does a fly away. I always use a spotter so depending on building height and conditions may try that in the future