Correcting merged LiDAR DEM with outliers in inner edges?

Question

I've created a DEM from LiDAR data. After combining all the files, I could see that there are some problems through the tile borders. This is an screen focused in one of the cross section of 4 files connected.

All the values are around 800m, while the "black lines" contain values around 400. I'm looking for a raster tool where those values can be interpolated.

Here is the peace of raster (.tif, epsg:25829) to try by yourself. https://drive.google.com/open?id=18LgIp6VNyCphDpnRVPlZelLFd3m8JF4y

Answer 1

If you’re using FUSION, you might have to look at the LTKProcessor to retile your data to include buffer overlap. See Appendix C of the FUSION manual http://forsys.cfr.washington.edu/fusion/FUSION_manual.pdf

If you don’t have too many tiles, you could also use the FUSION “MergeData” program to combine all your point cloud files prior to interpolation.

If you have license to LAStools, you can use the las2dem tool with the -merged flag to avoid edge artifacts.

If you have ArcGIS and the “standard” or higher license, or 3D or Spatial Analyst extensions, you can create a LAS Dataset or all your LAS files, then use the “LAS Dataset to Raster” tool.

Also, as a side note, if you’re sticking with FUSION, you don’t need to decompress your LAZ files if you take the LASzip.dll file from your LASzip folder and place it in your FUSION install directory.

Whichever method/software you use, interpolating from the point cloud is preferred over trying to modify your already existing raster.

Answer 2

I found another way to solve the problem:

1. Merging .laz files if you just have an small area.
2. Using lastilepro (lastools) first. Similar to LTKProcessor you can define a buffer and extension of .laz files.

After processing with canopy, ground filter, etc, the merged DEM has no weird "lines".