Hillshade coming out pixelated after using the Mosaic to New Raster tool to merge DEM's

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03-21-2023 06:09 PM
SeanM
by
New Contributor II

I am trying to create a hillshade from  DEM datasets. When I run the hillshade tool on just one of the datasets, it turns out fine. But when I use the Mosaic to New Rater tool to merge 2 DEM datasets and then run the hillshade tool, it turns out super pixelated. I'm not sure what's causing this, and I've changed every resampling method that i can find to bilinear and I am stumped. 

Attached are the hillshade using a single DEM dataset, which turns out fine and the hillshade after merging the same exact DEM dataset with the one next to it for a larger area than the first. 

4 Replies
DanPatterson
MVP Esteemed Contributor

If the dems were side-by-side, they should have the same properties and you shouldn't have had to change any of the optional parameters... What were your too inputs?

Mosaic To New Raster (Data Management)—ArcGIS Pro | Documentation


... sort of retired...
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SeanM
by
New Contributor II

Here is the dems side by side, the reason I'm running the mosaic is because they both have a different min and max elevation so the symbolization isn't the same. 

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SeanM
by
New Contributor II

And the DEM looks fine after the mosaic (here it is clipped to my area of focus so its smaller), but the hillshade is what turns out bad. 

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EvanR
by
New Contributor III

I just had the exact same problem and eventually figured it out. When you run the Mosaic to New Raster tool, make sure you select one of the "float" pixel types, otherwise the pixel values in the mosaic will all be converted to integers, which will result in the pixelated/contoured hillshade effect. ESRI's "Terrain: Multi-Directional Hillshade" layer from the Living Atlas is another option.

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