Applying for Altitude Waiver (107.51b) - waste of time?

[Kristina Fowler]

[Phantom 4 Pro]

I have a new client who has a work environment of approx 800 acres - approx 3,200' x 3,700'. He wants to get a usable image that takes in the entire 800 acres in one shot. Its possible (at 400') to shoot multiple overlapping photos and stitch them in Photoshop for a 2D pano, but the distortion is horrible. I estimate I need to go to at least 1,000' or even 2,000' to get a usable image of the 800 acres. When I say usable, I mean no greater oblique than 20 degrees from perpendicular to the ground.

There has been only 7 (seven) Part 107.51b waivers granted. Is it a waste of my time to even consider applying for an altitude waiver?

 

[N017RW]

The answer is always NO if you don't ask.
Why not pursue?
It will be granted on the merits of the Safety (risk) and the diligence of your application details.

 

[Meta4]

I have a new client who has a work environment of approx 800 acres - approx 3,200' x 3,700'. He wants to get a usable image that takes in the entire 800 acres in one shot. Its possible (at 400') to shoot multiple overlapping photos and stitch them in Photoshop for a 2D pano, but the distortion is horrible. I estimate I need to go to at least 1,000' or even 2,000' to get a usable image of the 800 acres. When I say usable, I mean no greater oblique than 20 degrees from perpendicular to the ground.

Running the numbers ... If you flew to 2000 ft above ground level, the area your lens would cover would be 3000 x 2000 ft.

To get the whole area in one shot, you'd have to fly to 3200 ft and your area covered would be 4800 x 3200.

Clearly this isn't going to work with the Phantom and there's no point asking for that waiver.

You'll either have to shoot obliques or if you want a vertical you'll need to do something like a DroneDeploy mission to create an orthophoto (Photoshop is not a good tool for that kind of stitching.
Looking at DD to get a rough idea of what's involved, it looks like it would take about 4 batteries at 400 ft and there would be a large number of overlapping images to stitch (a few hundred).

At 600 ft that brings the flight time down to 40 minutes.

 

[El Schue]

Running the numbers ... If you flew to 2000 ft above ground level, the area your lens would cover would be 3000 x 2000 ft.

To get the whole area in one shot, you'd have to fly to 3200 ft and your area covered would be 4800 x 3200.

Clearly this isn't going to work with the Phantom and there's no point asking for that waiver.

You'll either have to shoot obliques or if you want a vertical you'll need to do something like a DroneDeploy mission to create an orthophoto (Photoshop is not a good tool for that kind of stitching.
Looking at DD to get a rough idea of what's involved, it looks like it would take about 4 batteries at 400 ft and there would be a large number of overlapping images to stitch (a few hundred).

At 600 ft that brings the flight time down to 40 minutes.

Pix4D Mapper Pro offers a 15 day free trial that can do a good job and also offers 3D modeling. It's similar to Drone Deploy I believe. There is a little animated look to it, not like a true photo, but it is scalable and offers a volume measurement tool as well. By the way I'm new to this forum and look forward to learning from you all. Thanks.

 

[Kristina Fowler]

Running the numbers ... If you flew to 2000 ft above ground level, the area your lens would cover would be 3000 x 2000 ft.

To get the whole area in one shot, you'd have to fly to 3200 ft and your area covered would be 4800 x 3200.

Clearly this isn't going to work with the Phantom and there's no point asking for that waiver.

You'll either have to shoot obliques or if you want a vertical you'll need to do something like a DroneDeploy mission to create an orthophoto (Photoshop is not a good tool for that kind of stitching.
Looking at DD to get a rough idea of what's involved, it looks like it would take about 4 batteries at 400 ft and there would be a large number of overlapping images to stitch (a few hundred).

At 600 ft that brings the flight time down to 40 minutes.

This makes sense. I'm familiar with 2D ortho, but I was merely trying to accommodate the client. If I do apply for the waiver, I'll probably ask for 600' to expedite mission time.... but at least I know that 400 is doable.

 

[BigAl07]

You'd probably be better off hiring a pilot to take you up and shooting the pics with a good solid DSLR system. Less hassle and more likelihood of saving the job.

 

[Meta4]

You'd probably be better off hiring a pilot to take you up and shooting the pics with a good solid DSLR system. Less hassle and more likelihood of saving the job.

Yes ... it's doable as a big orthophoto.
But its a very big one.

 

[Meta4]

This makes sense. I'm familiar with 2D ortho, but I was merely trying to accommodate the client. If I do apply for the waiver, I'll probably ask for 600' to expedite mission time.... but at least I know that 400 is doable.

The Drone Deploy app is very good for planning and what-if scenarios.

 

[Richard R]

The Drone Deploy app is very good for planning and what-if scenarios.

I use both the DD app and the Map Pilot app by Maps Made Easy. MP too will allow you to preplan the mission, set altitudes to get the desired ground resolution and allows multiple battery missions. Small maps can often be processed in MME at no costs. I've done ones up to 50 acres. For larger maps, and yours would certainly qualify, you buy points from MME on an as needed basis. Costs are pretty reasonable. Once uploaded and processed, you can either give the client the image or direct him to the website where he can pull up his map and do things like determine the locations of points and object in the map or measure the distances between points.