jamie.finney

Merge lidar & sar without elevation step

Discussion created by jamie.finney on Feb 2, 2011
Hi has anyone had any luck coming up with a routine in ArcMap to merge different DEM datasets without steps in elevation where they join?

Often we have lidar data for cities but have to rely on sar for more rural areas and on the urban outskirts and merge the 2 datasets into 1 layer for running simulations. This can lead to steps in elevation where the datasets merge which can result in problems when performing water flow modeling where water will get stuck behind these "walls" where the data steps.

is there a good routine for merging datasets which would keep the more accurate lidar where available while trimming it so that there is a smooth transition between the datasets?

One idea i've had would be to use raster calculator to minus the lidar from the sar and re-classify all difference values that are <5-10cm and leave everything else as nodata. this should allow a merged cutline to be made which should eliminate most of the problems. though i think this would be a pretty manual process.

Has anyone else found a better way?

I have access to ArcView 10 and Spatial Analyst

Outcomes