How do I make sure I get full lidar point cloud?

[pannaga-kovari]

I am working with L2 lidar. I have installed unitree_lidar_ros2 pkg and using launch.py, but I am not sure why I am getting partial pointclouds. How do I make sure I get full lidar point clouds, and get rid of these streaks? Any help would be appreciated.
Thanks!

[markgol]

@pannaga-kovari
It is not clear you are not getting the full point cloud. You can characterize the image into 2 sample aliasing categories, streaks and rings. The streak represents a frame of points from one revolution of the fast scanner. The slow scanner is rotating so the next frame (streak) is at a different angular position. Overtime the slow scan fills in the various frame (streak) positions. The rings you see are the results of digitizing steps in the measurement of the return time laser pulse. Multiple reflections from reflective surfaces like glass (windows, picture frames, mirrors also give you interesting patterns. The only way to ensure you are getting all points is to track packet drops of frames. There is also generally a limit in the point cloud viewer for a maximum number of points or max time persistence of points. When the cloud reaches it max number of points or a certain amount of time has elapsed for the older points, These points re deleted from the displayed data and replaced with the newest points. The point density will be greater the closer the point is to the unit. The L2 unit captures a point as 2 angular measurements, distance (from time of return) and intensity. The angular positions and the distance are used to compute an x,y,z position.