The best approach to assign elevation to points from DTM

[VaL]

Hi all,

I have one points FC with about 5000 points. Their maximum bounding rectangle is 50 by 50 km. 

I also have 2500 1m resolution DTM elevation ASC grids. Total size is 17.5 GB OS grid data. 

What is the best approach to assign elevation to my points from those grids? Caveat is that while the points cover the 50by50 km area, there are location where there are no points. 

I have access to spatial analyst. 

Any ideas appreciated. 

[JayantaPoddar]

If you are looking to extract the elevation values to the existing overlapping 5000 points, you could use Extract Multi Values to Points (Spatial Analyst)—ArcGIS Pro | Documentation.

*Consider saving the output as a File Geodatabase.

You might want to use the tool with small batches of Rasters.

[VaL]

Yes, I am aware of that. However I have to load 2500 grids in the tool. 

They are all in different folders. Even then I am not sure it will succeed, because of size. 

[MehdiPira1]

@VaL ,

you can also use "Add Surface Information" which attributes features with spatial information from a surface like DTM.

https://pro.arcgis.com/en/pro-app/2.8/tool-reference/3d-analyst/add-surface-information.htm

[VaL]

@MehdiPira1 

Thanks. I know I can use a few tools from the SA toolbox. 

Question regarding the 'tool overload' still remains. 

I don't want to run the points against 2500 grids. Hence the question about how to strategy this. 

[Anonymous User]

Hi Val:

You could put the grids into a mosaic dataset first, then run one of the extraction tools on that.

However, I think using 2500 input raster datasets should work fine with emv2p or the sample tool. I recommend that you do this from python (build a python array of input grids) instead of trying to run the tool interactively using  2500 map layers.

Let me know how it works.

-Jim TenBrink

spatial analyst team