Is this even possible?


I’m looking to map this trestle. It’s over 450m long and about 60m high. I don’t think a Point of Interest mission will work. Low altitude flights to capture the framework will inevitably include the horizon, and yet the overhead grid won’t show enough detail.
Thoughts? Suggestions? Just run away??

@northarrow, my only thought is thatbit would be awesome to see the final project if it works for you.

Good luck !

A combination of vertical and oblique views should work OK. Do some 45 degree angle shots with no sky onto the side structure and then maybe some runs along each side with the lattice structure blocking the sky. Do a structure process and the outside at least should look OK. I think the complex internal lattice will probably process badly though, just too complex for the algorithm

If you don’t really need mapping outputs, why not shoot it as a panorama?

In my use I’ve found that is will likely map the outer surface as being a solid surface since it cannot see relative points inside the intricate structure from multiple angles. I haven’t used lower individual shots to try to add that inner detail as it wasn’t necessary, but that should be the result. Please update us with some results no matter how good or bad they may be.

I have yet to make out to this site. Work restrictions, weather restrictions, and Canada’s Thanksgiving holiday have all diverted my attention. I will let you know how it works out.

@northarrow This could be a very cool 3D structure if it processes. I would recommend flying a regular Nadir image mission followed by an oblique mission at 2 different altitudes. The thing to remember about oblique imagery is that they have a diminishing return. If you think of the drone like a spray paint can and your images like the paint, when you fly the mission you only need one layer of paint. Oblique images can cause a map to take much longer than normal to stitch or fail all together. Please let us know how this mission goes. This will be a great map if it can stitch!

Thanks @zach1. About the oblique mission: is this done manually in DJI Go?

Yes with DJI Go either manually circling the drone around, or use the point of interest feature to auto circle around a given point using timed shots or manual shots

I have to be careful with this site, and fly it on a slow weekend (whenever the weather starts cooperating). That’s a military airbase with pesky CF-18s flying around getting in my way! Once I get out there, I’ll have to keep an ear open and a finger ready to land the UAV, not just now, but RIGHT now!!

You have checked the airspace classifications and flight reatrictions, right :stuck_out_tongue_winking_eye:

ummmm… I’m going to say — yes…?
kidding aside- yes, of course I have. That’s why this isn’t done yet…

@northarrow Were you able to fly this mission? I would recommend filing a NOTAM on the DJI Geo website just to be sure about the airspace issues that could come up. This would be a pretty cool map! If you’ve already executed the mission I would love to see the map!

I wish it were as easy as filing a NOTAM.
I will need to apply for a SFOC, have written permission from the Base Commander and ATC, have communication with the tower, and then file the NOTAM. That’s too many ducks to line up in a row just to take a pretty picture.
This is in military class D airspace, and in this location that includes the surface to 8000’ (6200’ AAE)
I’m not saying I’ll never get to this but did I mention it’s -32ºC outside?

The airspace around here SUCKS!