Yeah, well we own a missile silo and have a YouTube channel where we go through the process of renovation into a home. Would be great to have some drone video for the channel.
Anyway, I tried to take some video of going from ground level down the access portal (35 feet below ground). The app showed negative altitude but after I decended it wouldn't let me go back up any above -15 feet. It kept saying max altitude. Which is weird.

Another issue, when underground of course have no GPS and everything is either concrete or metal. The compass was all out of whack too.

So the question is, what would be good settings in order to be able to fly in these conditions? Ideally obstacle avoidance would be on b/c it can be kind of tight quarters.

Thank you in advance for any help!

GT

It's a cool idea with a silo :-) Anyhow - the height limit - are you flying in beginner mode? Do double check this in the settings - otherwise you should be able to go down to any height below zero and you should be ok. There's nothing you can do about the compass destabilizing due to the metal interference - you do need the compass to work and you will just have to depend on your luck and piloting skills to make it happen. I'd advise quite a bit of practice before you do fly through the structure later on. Happy filming :-)

Wow, how cool is that? Love to see what you are doing with it -- what's the youtube channel url?

Anyway, see pg. 49 in the manual:

Height is restricted to 16 feet (5 meters) when the GPS signal is weak and Downward Vision System is activated. Height is restricted to 98 feet (30 meters) when the GPS signal is weak and Downward Vision System is inactivated.

I guess what this really means is that there are height limits when the Mavic is in ATTI mode.

Tripod mode seems to be what people are recommending for indoor filming.

The Mavic wants to stay within 5m of the ground so it can make use of the VPS system. You can disable the VPS to force ATTI mode if you're confident in being able to control it. I don't know how tight the space is. A set of prop guards might be a good idea, just in case :-)

Silo in Chernobyl?

Found you can put a flashlight on the floor, that will keep opti mode happy.

There are NO good settings. Compass don't go well with metal.

Thank you for the answers so far. You can go to dwbs.video if you guys want to see the channel.

So there's no setting I need to change? Underground its automatically in ATTI. But I get all kinds of compass warnings. And it for sure wanders a lot. Prop guards are in my future for sure. :-)

Any other thoughts are appreciated!

GT

rnrnrn Posted at 2017-1-29 15:23
It's a cool idea with a silo :-) Anyhow - the height limit - are you flying in beginner mode? Do double check this in the settings - otherwise you should be able to go down to any height below zero and you should be ok. There's nothing you can do about the compass destabilizing due to the metal interference - you do need the compass to work and you will just have to depend on your luck and piloting skills to make it happen. I'd advise quite a bit of practice before you do fly through the structure later on. Happy filming :-)

Wasn't in beginner mode. And it did let me go down... it just didn't let me go back up anything more than -15 feet.

GT

I'm sure you went into ATTI mode on the way down. When in ATTI mode, the Max height is 15 feet. Hence your limited climb. You'll have to film a descent and reverse it if you want it to look like you are going up.

Other than that, plenty of light, know that the downward sensors won't work on reflective surfaces and ALWAYS be ready to FLY the Mavic if it begins to drift.

Gary Mac Posted at 2017-1-29 20:44
I'm sure you went into ATTI mode on the way down. When in ATTI mode, the Max height is 15 feet. Hence your limited climb. You'll have to film a descent and reverse it if you want it to look like you are going up.

Other than that, plenty of light, know that the downward sensors won't work on reflective surfaces and ALWAYS be ready to FLY the Mavic if it begins to drift.

Actually, I think it went into OPTI mode, not ATTI. In pure ATTI mode, the height limit is about 100ft. I think what happened is that as it got close enough to the bottom of the silo, the VPS was able to see the bottom and it switched from ATTI to OPTI. That's assuming there was enough light at the bottom for OPTI mode to work. If so, once in OPTI mode it would not want to ascend more than 16ft from the bottom, unless VPS is switched off, forcing it back into ATTI mode. But if it was too dark for OPTI mode to work, then I can't see why it would not have ascended back up the silo, since ATTI mode height limit is supposed to be 98ft.

Jason Lane Posted at 2017-1-29 23:33
Actually, I think it went into OPTI mode, not ATTI. In pure ATTI mode, the height limit is about 100ft. I think what happened is that as it got close enough to the bottom of the silo, the VPS was able to see the bottom and it switched from ATTI to OPTI. That's assuming there was enough light at the bottom for OPTI mode to work. If so, once in OPTI mode it would not want to ascend more than 16ft from the bottom, unless VPS is switched off, forcing it back into ATTI mode. But if it was too dark for OPTI mode to work, then I can't see why it would not have ascended back up the silo, since ATTI mode height limit is supposed to be 98ft.

Thanks for the correction. I always blur the lines between OPTI and ATTI modes. Good catch.

I'm bumping this to see what my options are. What is the function of the compass? Can it be disabled? Thanks! - GT

I can't give much advice, but all I wanted to say is, if you own a missile silo... WE WANT TO SEE IT!!!

CuaC Posted at 2017-1-31 02:10
I can't give much advice, but all I wanted to say is, if you own a missile silo... WE WANT TO SEE IT!!!

Thanks. We have a YouTube channel about it and plan on using the Mavic to help with it. www.dwbs.video will get you there.

GT

I expect the compass is used to determine nose orientation of the craft and maybe as a navigational input?

DWBunnySlippers Posted at 2017-1-31 06:39
Thanks. We have a YouTube channel about it and plan on using the Mavic to help with it. www.dwbs.video will get you there.

GT

Cool! I'll take a look at it!

@DWBunnySlippers I too have a similar issue, I've been asked to video the large Crossrail tunnels being built under London, these things are MASSIVE. I've got a fair few hours Mavic filming under my belt so I'm ok with the idea of flying without GPS, but am curious to know how the drone will cope with the lack of GPS/compass. Will it let me fly? if so hight and distance info would be good to know. I don't want to get on set and find I'm grounded. Thanks in advance. p.s. here are the tunnels http://christoffer.co/no-name-yet

Just attach 2 strings to the Mavic and use some pulleys.

I wish there was a single button in the GO app called "Indoor Mode" or something similar that we could select to set all the appropriate settings rather than have to individually go thru them all then again to set them back for outdoor flying. Simple and seemless.

Hello all! know it's been a while... wow... a long while.

Bumping this to see if there's any new suggestions. I have a Mavic Pro and Mavic Air.

Thanks!

GT