Handling Lidar Point Clouds In Pix4D

PIX4Dsurvey
1

We are thinking about getting a drone with lidar and I have some questions hopefully someone can answer. We currently use an M210 with a zenmuse X4S. We set ground control points that are on our local state plane coordinate system and are scaled to the ground so that our drone outputs(ortho image, contours,…etc) match all our survey data that our field crews collect with traditional survey equipment. My question is. If I get an RTK drone with lidar how do I make the lidar point cloud match the same datum as out field crews survey work? There are no ground control points for lidar. I believe you can get it to issue corrections to the drones rtk system on your local state plane system but from what I understand that is on the grid and not scaled to the ground. Unless I am incorrect. If anyone has any input I would appreciate it. We are looking at a DJI M300 with the Zenmuse L1 Lidar. Thanks in advance.

-Josh

2

Hi @Joshua_Riedy,

That’s a good question. Since the L1 point cloud has to be processed through Terra, I would expect that they offer the grid to ground correction there before creating/exporting a .las file, but I haven’t tested, so can’t confirm.

At the same time, the L1 has a camera on board to colorize (normally), and with that you should be able to pick out GCP in the point cloud. You might also be able to use those to fit to the ground in Terra. I’ll be curious to hear if anyone else had tried this out and had any success. Good luck!
Nate