Mapping Under Trees

We do allot of refurbishing of parking lots and we fly them and get a great highres orthomosaic. But we then have to field measure the areas under the trees. How might we supplement our images to get better coverage under trees? Obviously we would use Full 3D processing but can we mix low altitude 30ft high ortho images orbiting around the trees with our 150ft nadir images? Looking for some ideas.

Christopher Gmuer February 07, 2024 01:04

Official comment

You can mix altitudes but that is a pretty severe difference. I would try to get a bunch of views of that area and remove as many as you can that include the covering trees. Try to keep it to half, not 1/5.

The Full 3D model should have the ground detail but you would have to do your measurements on the 3D model since it is possible that the areas you care about would be obscured by the top down resampling of the ortho image.

Zane February 07, 2024 02:53

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3 comments

Could I also filter out and remove images of the tree canopy from the nadir images? In other words, I fly a low pattern over the parking lot at 90ft (just above our 70ft trees) and then manually fly at 30ft taking ortho photos under the tree canopy, and then remove images that include tree canopy from both sets of photos. From what you say it might work and worth a shot.

Christopher Gmuer February 07, 2024 03:15 0 votes

The idea would be to remove the images that show the trees overhanging what you want to look at. That way they might not render and leave you with the view of the ground.

You could also tip the gimbal up a bit (25 degrees or so) to view in under the trees. One pass will have the view under the trees and the next will have a lot of tree covering what you want to look at. Remove those images.

Zane February 07, 2024 16:08 0 votes