I have already converted the point cloud data into a matrix of 5 columns. But I am unable to detect the ground planes/ground reflections in this data. Can you help?

# How to get the ground planes in a given LIDAR point cloud data

Ground plane detection is a very complex problem. If you just want a very simple algorithm you could use the 5(?)-percentile along the z dimension. Or even the median. Then you get a horizontal ground plane estimate.

I was advised by some experts to use the RANSAC algorithm to detect the ground plane. Is 5(?)-percentile simpler than that ?

Any of the methods I described would just give you a perfectly horizontal plane. For proper plane fitting with arbitrary orientation RANSAC is indeed the standard solution. I suggest you google for some tutorialsâ€¦

Thank you for the information. I shall seek the same