Associated surfaces extend out beyond the site extent

[dbaumer21]

When deriving point density and slope associated surfaces, I get a raster that extends out of the site (a large square). I used a .shp file from the raw topographic data. I am also getting a message that says the projection doesn't match, and the authority doesn't match the coordinates. How do I fix that? I am guessing that might be the problem. Here are some pictures:

Another unrelated question: What are the pros/cons of using a round vs. a square derivation method?

[philipbaileynar]

If you are convinced that the source ShapeFile has the correct projection then use the ArcGIS Define Projection tool, using one of your DEMs as the source of the map projection. This will not alter the source ShapeFile data. It will merely redefine the map project associated with the ShapeFile.

If however there is the slightest chance that the source ShapeFile does indeed have a different map projection then you should use the ArcGIS Project GeoProcessing tool, again using one of your DEMs as the target map projection, to reproject the source ShapeFile to the same map projection used by your DEMs. This will alter the source ShapeFile!

The links above are to ArcPro, but the same tools exist in ArcGIS 10.x.

[dbaumer21]

Thank you!

…

On Wed, Feb 2, 2022 at 10:23 AM Philip Bailey ***@***.***> wrote: If you are convinced that the source ShapeFile has the correct projection then use the ArcGIS Define Projection <https://pro.arcgis.com/en/pro-app/latest/tool-reference/data-management/define-projection.htm> tool, using one of your DEMs as the source of the map projection. This will not alter the source ShapeFile data. It will merely redefine the map project associated with the ShapeFile. If however there is the slightest chance that the source ShapeFile does indeed have a different map projection then you should use the ArcGIS Project <https://pro.arcgis.com/en/pro-app/latest/tool-reference/data-management/project.htm> GeoProcessing tool, again using one of your DEMs as the target map projection, to reproject the source ShapeFile to the same map projection used by your DEMs. This will alter the source ShapeFile! The links above are to ArcPro, but the same tools exist in ArcGIS 10.x. — Reply to this email directly, view it on GitHub <#424 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AXRXTSOHDH6NZ3IPMSD7CMTUZFSB5ANCNFSM5NJ2NF6A> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. You are receiving this because you authored the thread.Message ID: ***@***.***>

[joewheaton]

@philipbaileynar I have seen this behavior @dbaumer21 describes previously and I'm pretty sure we posted it in #351. I don't think this has anything to do with an incorrect projection in my experience. It has to do with the associated surfaces that we create for the user NOT effectively applying the NoData mask. This is something that the ESRI geoprocessing tools do too incorrectly. I just don't think we're applying our own workflows and rules. I think these density algorithms are correctly applying a moving window and calculating zero for the rest of that data extent instead of using the NoData mask.

@dbaumer21 you asked:

Another unrelated question: What are the pros/cons of using a round vs. a square derivation method?

The round tends to have a smoother transition and produce slightly lower point counts because it is sampling a smaller area for the same radius/cell count out. This is of little consequence and is really only something for the person making the fuzzy inference system to be aware of in what they use/take to mean low, medium and high. I would just stick with the square as it is what is more commonly used in literature when people report point density.

[philipbaileynar]

Are there two problems here? #351 is legit and needs addressing. But the projection warning feels like a separate issue?

[joewheaton]

You might be right @philipbaileynar. I am not sure about the projection thing, but I suspect it is separate issue.