Hi all, I'm trying to calculate the height from the ground of several lidar points (15million) in order to get the number of points that occur at different height levels. I read some older posts about using r.in.xyz (or r.in.lidar in grass 7) but I could not understand how to count the number or points that have height from 0 to 5 m above the ground, for instance. So, I'm trying to do the following.
1) import points using v.in.lidar (Grass 7 ubuntu linux) 2) create a column in the database for the ground height and one for elevation 3) populate height column from ground raster (generate in another process) using v.what.rast 4) calculate elevation as zcoord - ground for each point (v.db.update) As you might imagine, this takes a long time. Just to import a 400Mb lidar file takes around 50min. Is there any easier way that I'm not envisioning? I'm running Grass 7 with liblas on a Ubuntu Virtual Machine and sqlite backend. Thanks Daniel _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
