PFTrack Support Community

Good evening all,

I am a collision investigator and am trying to determine the proper method to track a vehicle's dashcam when LiDAR survey data of the roadway and environment is available.

Importantly, I am trying to get a good track for the camera, and then set the coordinate system and scale based on the 3D coordinates of the LiDAR survey. That way, I know the camera position in real-world coordinates, so the vehicle can be placed on the roadway and speeds can be calculated based on frame timing.

My current node structure goes:

• Clip input (where the frames from the video are imported as JPGs)

• User track. Here I carefully created 60 trackers that span substantial segments of the 4.6 video. Coverage looks good, with something like at least 10 trackers per frame.

• Survey Solver. Here I imported the LiDAR and attached the 3D coordinates from the survey to 14 of the trackers, in hopes of defining the coordinate system/scale.

Is this the proper workflow?

When I solve with the Survey Solver, it does not properly track the camera. The residuals on the trackers is huge, with the largest being 450 and the average at ~100. I accounted for distortion with the straight line method, but the video I'm using here was shot with a GoPro in linear mode, so I'm not expecting big distortion capable of blowing the project up.

Thanks for any help!

Lou