How would I fix my DEM because it has holes?
I need to maybe extrapolate from surrounding terrain.
Here is the picture
There is a elevation void raster function in arcmap. This function uses the Plane Fitting/IDW void fill method. First a basic method is used, where the average of the eight neighboring values are calculated to fill small voids, then the plane fitting method is applied. If the error of the plane fitting method is too large, an inverse distance weighted (IDW) algorithm is applied.
It's a raster function and needs to be applied as part of a function chain. (C/O Luke)
The first answer on this GeoNet post makes sense to me. It reads:
I use the following method to fill gaps in DEM. I uses a moving window that searches the DEM for Null data values and fills them with an average of the surrounding pixels.
new_DEM_name = con(isnull(old_DEM_name), focalmean(old_DEM_name, rectangle,4,4), old_DEM_name)
change "new_DEM_name" to anything that you want. "old_DEM_name" is the name of your DEM that has gaps in the data. You can adjust the size of the window by change 4,4 to 6,6 or anything you want.
answer credits : jmeisel