Ditched drones for lidar scanning on a big site and it paid off big time

Had a 12 acre lot in Austin that we needed to map for drainage planning. The crew was split on using a DJI drone for photogrammetry versus going with a Leica BLK lidar unit. I pushed for lidar because we had heavy tree cover and I didn't want to mess with stitching hundreds of images. Drones are cool but that canopy would have wrecked the accuracy. Spent about $400 extra on the rental but we got the whole site mapped in 4 hours instead of 2 days. The point cloud cut through the trees clean and the grading plan came out perfect. My main question is has anyone else run into photogrammetry failing hard in wooded areas or is it just me?

2 comments

2 Comments

xena5824h ago

Man honestly I used to swear by photogrammetry for everything, but your story just clicked something for me. I had a similar sized job near Seattle last year with heavy doug fir coverage and the drone output was a nightmare to clean up. The tree shadows created weird gaps and the final mesh had these random holes that took forever to patch. After reading this I'm definitely gonna push for lidar next time the tree cover gets thick. The speed difference alone sounds worth the extra cost.

harperp242h ago

Bring up something nobody's talking about though - how much of a pain it is to store and process all that lidar data. I got a quote for a project last month and the raw point cloud file was like 40 gigs before I even started cleaning it up. My old laptop couldn't even open it without crashing. If you go lidar make sure your computer can actually handle it.