Launch from a moving ship?

MrRobville · Mar 5, 2018

Hi there,
With models like the Phantom, I've once read that you could launch the drone from a moving ship if you set it to Atti mode instead of GPS, to avoid the drone hovering away.
I was wondering, would such a thing be possible to achieve with the Mavic Air? I recall it doesn't have an Atti switch and can only fly in GPS mode. But contrary to the Phantom (3) it does have visual position sensors.

Can anyone shed a light on this?

waddellw · Mar 5, 2018

MrRobville said:
Hi there,
With models like the Phantom, I've once read that you could launch the drone from a moving ship if you set it to Atti mode instead of GPS, to avoid the drone hovering away.
I was wondering, would such a thing be possible to achieve with the Mavic Air? I recall it doesn't have an Atti switch and can only fly in GPS mode. But contrary to the Phantom (3) it does have visual position sensors.

Can anyone shed a light on this?

Can't comment on the ATTI switch, but imagine it initiating RTH... That would be awful having to watch it fly away....

coullit · Mar 5, 2018

Ah but you can set the rth to your current position, have a look in settings.
best to find a flat spot on boat to take off with no obstacles or cables nearby.
hand landing is often used and can turn off in settings lower sensor that will keep detecting your hand.

Simmo · Mar 5, 2018

coullit said:
Ah but you can set the rth to your current position, have a look in settings.
best to find a flat spot on boat to take off with no obstacles or cables nearby.
hand landing is often used and can turn off in settings lower sensor that will keep detecting your hand.

Only if your device has a gps module. Seemingly most apple products dont??
And if all was good with that, you would have to set the RTH HP to ME, before pressing RTH, or it will go to where you were....

EDIT: Fairdinkum, I write this to help out and then see that its a frikkin Mavic AIR.... sorry Bud, dont have one ....dont know...

Lake_Flyer · Mar 5, 2018

Stationary vessel ok but on a moving vessel I wouldn't do it without lockable Atti mode.

Vaisraitor · Mar 5, 2018

I also want to do this but with the OG Mavic Pro.. We sail mostly during nighttime so to pick a good day with proper daylight, good weather conditions i.e. clear skies, not to much wind is tricky but doable. I've read before you should always consider your speed and windspeed relative to the ship to make sure you can come back if you fall behind the moving vessel whilst filmen / taking photo's. For me, sailing on a container vessel it's tricky to find a clear spot on the vessel to take off from / Landing. Perhaps handpalm landing is an idea but not easy to do on your own. The thing that worries me the most is the compass error that all this metal will generate.. Deviation. Is it possible to fly with a (big) compass error on the mavic? Also do the ships antenna's (VHF / MF-HF / Inmarsat / RADAR's) disturb the signal between the remote and the mavic?

A2 Drone · Mar 5, 2018

I launched from my small Seadoo boat, at drift, trying to film some shrimp boats in the dock. I had planned on taking off and land on the large sun pad on the back of the boat. During take off I had to calibrate the compass and just took off from the top of a cooler on the back of the boat. Then it hit me, the big speakers built in to the back of the boat were causing the compass error. Well now i was adrift and had to land in my hand, while needing two hands to fly forward and down. It worked out ok, but try to to avoid metal or magnets, If the ship is metal.

Vaisraitor · Mar 5, 2018

Since is a seagoing container vessel it's steel all the way.. What will be the issue's of flying with a (big) compass error? Heading and RTH (partly) make use of the compass.. But if you fly in a way you can always see the drone it doesn't matter if it's heading is off since you can fly it manually back.. RTH is tricky anyways because of the vessels movement (Perhaps RTH set to location)

A2 Drone · Mar 5, 2018

I'm not sure how it acts with a compass error. The people flying inside and some others have said it is just a little erratic. You could see if it has an error when launched from your hand. But trying to land on your own hand while on a moving vessel is a bit of a challenge.

corchard · Mar 5, 2018

Vaisraitor said:
Since is a seagoing container vessel it's steel all the way.. What will be the issue's of flying with a (big) compass error? Heading and RTH (partly) make use of the compass.. But if you fly in a way you can always see the drone it doesn't matter if it's heading is off since you can fly it manually back.. RTH is tricky anyways because of the vessels movement (Perhaps RTH set to location)

The air is very sensitive to metal and won't fly with a compass error that I've been able to determine. I can't get closer than 8 feet from a steel outdoor patio table and pass a compass recalibration.

After calibration it takes off and lands on the steel table but I've had some random flight patterns around it at times.

MrRobville · Mar 6, 2018

I appreciate the replies. It seems like quite a tricky flight to perform then. As Vaisraitor pointed out, anything seagoing is pretty much all steel, even below wooden decks, so there are hardly any places to launch a drone from without being in the proximity of metal. Only thing I could think of is launching it from your palm, though that will only give about 2m clearance if held up high.

Simmo · Mar 6, 2018

MrRobville, can I ask if your ship has an old school compass in the bridge? (I dont care if the ship is commanded via wheel, joystick or Google)....
Could you also stand on the deck, and get an accurate compass reading to navigate your 120 mtr long vessel?
If so, then personally, I would be flying my butt off.... Granted, you need to be confident with landing on a moving object...

MrRobville · Mar 6, 2018

I have no designated vessel yet. However, I'm planning a trip in the near future where I'll be making a few crossings on sea, hence my interest on the matter. I think it would be great to capture a few seagoing shots, but only if I have a drone left afterwards of course.
What perhaps would be an idea, is to try to take off while the ship is still in port. If there is any compass interference, I would find it out instantly.

daisy-girl · Mar 6, 2018

Simmo said:
Only if your device has a gps module. Seemingly most apple products dont??
And if all was good with that, you would have to set the RTH HP to ME, before pressing RTH, or it will go to where you were....

What firmware does one need for the feature that automatically resets the ME home point for every 15m of change in location?

Simmo · Mar 6, 2018

That is DYNAMIC HOMEPOINT.
Firmware is the DJI proprietry stuff that operates the AC.
Software in the form of an App, DJI Go4, in Active track and with Dynamic HP enabled, will update the HP as you rightly say, to the position of the AC, not necessarily ME.
Litchi for that matter, a different software App, using the same firmware, has its Dynamic HP locate the device, ie ME, (should it have a gps module).

daisy-girl · Mar 6, 2018

Simmo said:
That is DYNAMIC HOMEPOINT.
Firmware is the DJI proprietry stuff that operates the AC.
Software in the form of an App, DJI Go4, in Active track and with Dynamic HP enabled, will update the HP as you rightly say, to the position of the AC, not necessarily ME.
Litchi for that matter, a different software App, using the same firmware, has its Dynamic HP locate the device, ie ME, (should it have a gps module).

Yes, I'm familiar with that, but I thought I read somewhere that the ME homepoint can also be automatically updated every 15m, provided one's device has GPS, i.e., WiFi + Cellular.

Simmo · Mar 6, 2018

Only with Litchi.

Simmo · Mar 6, 2018

I'm sorry, those two jpegs came out too close together. Obviously the bottom one is Go 4.

Vaisraitor · Mar 6, 2018

Simmo said:
MrRobville, can I ask if your ship has an old school compass in the bridge? (I dont care if the ship is commanded via wheel, joystick or Google)....
Could you also stand on the deck, and get an accurate compass reading to navigate your 120 mtr long vessel?
If so, then personally, I would be flying my butt off.... Granted, you need to be confident with landing on a moving object...

I'm not sure what you mean..? Sure there are at least two compasses on the bridge (Magmatic and Gyro most of the time) this info could someone standing on the bridge tell you by radio if you need it.. But what good is that info since you can't just tell the mavic what it's heading is.. [emoji14]