Compass calibration on a ship...

[cycoptic]

Hi , I have done this before , just do your compass calc before you get on.
These ships even though made of steel usually have the back deck with wood on it,
take off from this but make sure you get it in the air high enough so the compass
won't start freaking out. You will be good to go. When you land get it down fast before it lights up
like a christmas tree. I would turn it back on inside later so it could reset itself.

 

[tapcon]

Nice. Looked like that captain was about to have a meltdown

That line overhead was a concern as well.

But well done!

I had gotten permission from the Captain prior to launching.

 

[jonathan Atkin]

I am really appreciating the discussion regarding launching off a steel ship. It is a conundrum. My recent Inspire1 flight above a small coastal tanker worked well in GPS. Calibrated the compass in the parking lot in Brooklyn before boarding vsl. The tugboat capt was nice to turn off his radar. Whether that would have interfered I'm not sure. Flew in GPS for 90 minutes of flying aboard a very slow moving but moving none the less, vessel was successful. I may be on a cruise ship soon and then I may simply fly in ATI only. Remains to be seen. All suggestions welcome.

 

[cycoptic]

just launch off something that is not steel and you'll be all good once in the air.
Have fun

 

[jonathan Atkin]

just launch off something that is not steel and you'll be all good once in the air.
Have fun

We launched aboard the ship from a 1/2 " thick plywood sheet atop the deck. Not sure that had any effect on compass accuracy but we were successful. And yes, I made sure I gained quick altitude...to lock in GPS....before flying ATI. There are discussions that a 1/2" piece of wood is irrelevant on a steel decked ship. Most ships are totally steel. Everywhere.

 

[Scotflieger]

We launched aboard the ship from a 1/2 " thick plywood sheet atop the deck. Not sure that had any effect on compass accuracy but we were successful. And yes, I made sure I gained quick altitude...to lock in GPS....before flying ATI. There are discussions that a 1/2" piece of wood is irrelevant on a steel decked ship. Most ships are totally steel. Everywhere.

You are probably better doing your compass calibration on land in a benign environment before getting on the water.

 

[jonathan Atkin]

You are probably better doing your compass calibration on land in a benign environment before getting on the water.

YES. Exactly. We did the compass calibration in the Port Authority parking lot, about 50 feet way from the ship. But I'm likely to be aboard other ships in other ports, and at sea, and won't have that luxury.

 

[Scotflieger]

YES. Exactly. We did the compass calibration in the Port Authority parking lot, about 50 feet way from the ship. But I'm likely to be aboard other ships in other ports, and at sea, and won't have that luxury.

Only one word of caution. Be careful to avoid any concreted areas as they are likely to have a lot of steel reinforcing. The view of many is that, provided the compass values are between 1400 and 1500, compass calibration is unnecessary.

 

[jonathan Atkin]

I hear you. I check the compass mods. I did a flight at a shipyard, some months ago, before I had the Inspire, with my Phantom2. Shipyard has massive railroad tracks on the pier and it took about 15 minutes to find a spot where P2 would even calibrate or give permission to fly. but we did.

 

[Shazbot4]

take 2 pool noodles, cut them to how ever long you need them so the i1 floats on water, second, i thought they did an update a while back so you could launch a i1 from something that's moving?

 

[jonathan Atkin]

take 2 pool noodles, cut them to how ever long you need them so the i1 floats on water, second, i thought they did an update a while back so you could launch a i1 from something that's moving?

One can launch anything from anything. As for Pool noodles...sure, that will save the Inspire if she hits the water or at least the SD card....but she's not built to be stable on water or with electronics that will withstand same. There are several waterproof quads and hexacopters on the market however...one using a waterproof frame and waterproof GoPro and another with the camera inside the housing on the Zen Muse gimbal, with a waterproof Perspex window..which could conceivably lift a micro 4/3's sensor camera as well. The HEXACOPTERH2O uses all dji goodies. and has "noodles."

 

[SultanGris]

I think you guys are way over thinking this, you can launch from a piece of steel no problem, once you get a few feet in the air the interference will go away. I launch off my truck bed all the time within a foot of the metal box side(cover isnt metal) and ive launched from aluminum boats/docks with no problems. Compass doesnt matter unless youre in gps mode and its trying to hold position against wind or something and telling the craft to fly north when the craft thinks north is actually east or something due to compass error, thats bad. you shouldnt really be launching in gps mode from a ship anyway, especially if its moving as the inspire will hold position and crash if anything is behind it. use atti mode and switch to gps when your in the air. Being close to steel might cause calibration problems but calibration before every flight is not necessary. I dont know how sensitive it is to metal exactly but ive calibrated 3-4 feet from my vehicle with no issues.

 

[jonathan Atkin]

Thanks so much. On my Mary Whalen vid, I did launch in GPS mode with no issues from the steel ship. However I do appreciate the need to be in ATTI...and then once at some altitude one can switch happily to GPS...What do you mean: "Especially if its moving (YES most ships do) Inspire will hold position & crash if anything is behind it?" What do you mean by "anything behind it." ??? Part of the ship? another ship? a mast?

 

[jonathan Atkin]

I don't know if i posted this previously, but this was shot from deck of steel ship. We did Compass Calibration off the ship in the parking lot, whether re-bar was underneath I've no idea. Had no issues during the ship movement. Had an issue later that evening after 90 minutes of intense flying: Flew one last time off the parking lot and either I was exhausted (human error) or some other anomaly..and Inspire went wacky:..into a warehouse wall. Fortunately it did not crash into the East River.

 

[SultanGris]

part of the ship. gps holds stationary position in relation to the ground so if you take off in gps mode from a ship going 15mph the inspire will try and hold position it was in when you fired up the motors but since the launch platform is moving it wont be the spot you took off from, so if any part of the ship is higher than where you took off from, or if anyone is standing behind it there is likely risk of crash. If you take off from the rear of the ship and nothing is higher than the launch platform it will be ok but i read a thread where one guy launched from the front of a cruise ship and promptly crashed into the wall behind the launch location, expensive and embarrassing mistake.

 

[jonathan Atkin]

Thanks again. We took off from the Mary A. Whalen on the foredeck. And landed at least 10 times on the foredeck. She was moving about 2 knots at best, a very slow tow. And of course the ship's wheelhouse was higher than the launch site. Tho with the Inspire one can use "DYNAMIC HOME POSITIONING" to allow the Inspire to know where the RC is located, even if moving and I assume that might mitigate the Inspire's thinking of the actual launch site? However we did not invoke Dynamic Home Positioning on this project. Most ships do NOT have much room on the stern to launch drones......the foredeck on cargo ships is huge with wide open hatches often with a helo "H" and open and on cruise ships there is, often a helicopter deck on the bow. Open stern areas are rare.

 

[SultanGris]

problems will be less severe if the boat is moving slowly or stationary but as long as you are aware of the behavior and have enough room and react quickly taking off and clearing the ship fast then you could use gps mode without problems im sure, but be aware boats drift, and you might not think youre moving but very well could be so you wouldnt want to take off and try and hover a few feet from the deck for any length of time without paying attention if you know what i mean.

I really doubt the metal will have any effect on the compass if you have the room to launch in gps mode safely, but if it does using atti mode will negate the interference is all im saying.

 

[jonathan Atkin]

Indeed. We were very slow; almost stationary. At one time we were pushed 360 degrees..and yes, I had to keep fully focused to maintain Situational Awareness. The deck of the small tanker had booms and derricks and we most definitely had to lift off and clear same. I am a USCG Licensed Master so I'm very cognizant of ship movement. Been photographing ships from manned helicopters and on board for 20 years. But in the past 2 years I'm "ALL IN" with drones and exploring all my options. One question that wasn't answered by either friends in the maritime, aviation or drone community was whether radar on a ship would interfere with the drone telemetry. Conservatively, on the Mary A. Whalen vid, I asked the tugboat Captain to turn off his radar, to which he obliged, as I cited the USCG reg, that it wasn't necessary to operate, only to be operational in the small transit we were involved.

 

[SultanGris]

i couldnt say with 100% certainty but i would doubt radar would have an effect, unless maybe you were flying right next to it. Dont know what sort of signals/frequency its sending out. Ive never had any issues with interference using my cell phone to fly without shutting anything off, but some people think you need to use airplane mode to reduce interference. i dont find this to be true, it may be of benefit for battery saving and less cpu usage but thats it.

 

[lrwskyfilms]

I've done a shoot on a catamaran which had a aluminum hull and steel railings, decks etc as well as steel containers on board. As stated above do your compass cal and IMU cal at known good locations, do not do these onboard.

On start up my MODS went from 1450/1550 to 2700/2900, only when I took off and hovered about 10ft from the craft did the MODS drop to about 1500. I took off and landed in GPS mode, with my finger on the ATTI switch.

Also as the CAT hit 30+knots I cancelled the 500mtrs distance settings, otherwise you'll have to hit dynamic home point frequently.

I flew around the craft in the same waters as other boats/ships, no interference from sonar/radar/comms etc and no picture break-up.

The hardest bit was doing 30+ knots across others waves, holding on, keeping balance, keeping LOS and trying to film/shoot made it somewhat exciting.