topic Re: How do I add a vertical coordinate system to my raster so that I can run the new viewshed 2 tool? in ArcGIS Spatial Analyst Questions

How do I add a vertical coordinate system to my raster so that I can run the new viewshed 2 tool?

BriannaCarver1 — Mon, 04 Apr 2016 20:32:36 GMT

I want to use the new Viewshed 2 tool but when I put my raster into the tool it gives me warning 010451 which says "Input elevation raster should have a vertical coordinate system that has heights reference to a spheroid." The help page on this is very vague and I cannot figure out how to assign a vertical coordinate system to my raster. I have found pages saying that there is no way to project between vertical coordinate systems in ArcGIS but it seems like there must be some way to assign a vertical coordinate system to a raster so that you can use the Viewshed 2 tool. Is there a way to do this?

Re: How do I add a vertical coordinate system to my raster so that I can run the new viewshed 2 tool?

DanPatterson_Retired — Mon, 04 Apr 2016 21:58:29 GMT

Perhaps Melita Kennedy could shed some light on what the 3D people are to do, since there is truly a dirth of information to guide them in the help topic.

Re: How do I add a vertical coordinate system to my raster so that I can run the new viewshed 2 tool?

JosephChimento — Wed, 06 Apr 2016 17:56:33 GMT

I would also appreciate a response. I have tried to reproject my raster while explicitly stating the vertical coordinate system using a number of different ellipsoids (just to troubleshoot). Nothing worked.

Thanks!

Re: How do I add a vertical coordinate system to my raster so that I can run the new viewshed 2 tool?

MelitaKennedy — Thu, 07 Apr 2016 21:49:46 GMT

Brianna, I'm checking on it. As far as I'm aware, the Define Projection tool and a raster's property page do have VCS implemented yet. I just tried a 10.4.1 beta and don't see how to add a VCS to a raster.

Joseph, again, as far as I'm aware, rasters are not explicitly supporting vertical transformations yet. We just added that functionality for vector data to the Project Tool in ArcGIS for Desktop 10.4.0.

Melita

Re: How do I add a vertical coordinate system to my raster so that I can run the new viewshed 2 tool?

MelitaKennedy — Thu, 07 Apr 2016 22:49:07 GMT

If you use the Define Projection tool on a raster, you should have both the XY and Z coordinate system tabs. You must set the XY coordinate system first.

When I did this, I still could not see the vertical coordinate system when I looked at the spatial reference on the data's property page in catalog. If I opened the Geodata transform, then it was listed in its well-known text form.

Melita

Re: How do I add a vertical coordinate system to my raster so that I can run the new viewshed 2 tool?

DavidAllen — Thu, 28 Apr 2016 23:57:03 GMT

I had students facing this same problem. We had a file called BigBend in geographic coordinate system GCS_WGS_1984. Note that the units are in Degrees.

Take the unprojected elevation raster and use the Raster Calculator to create a Raster Attribute Table.

int(BigBend_dem.tif)

... new output something like BigBend_INT

The reproject the new file into UTM.

Project Raster - give it a new output file name (BigBend_Proj), set the resample technique to Cubic (NOT nearest) THEN

set the output to Projected Coordinate System > UTN > North America > Nad1983 HARN UTM Zone XX (whatever your UTM zone is).

Now try running the slope tool and let me know if that works.

Re: How do I add a vertical coordinate system to my raster so that I can run the new viewshed 2 tool?

EzekielBaye1 — Tue, 08 Nov 2016 21:16:52 GMT

Still not working, any update? I just tried to create a viewshed for a raster that has a vertical datum and still got the 010451 error.

Re: How do I add a vertical coordinate system to my raster so that I can run the new viewshed 2 tool?

XuguangWang — Tue, 08 Nov 2016 23:19:21 GMT

There are two types of vertical coordinate systems. One references a spheroid and the other references a gravity-related surface. See the following help page: Vertical datums—Help | ArcGIS for Desktop

Viewshed 2 require the height of the vertical coordinate system reference a spheroid. If it references a gravity-related surface, then the warning message 010451 will still show.

However, you should be able to run the tool and get a result even though the message is shown.

Re: How do I add a vertical coordinate system to my raster so that I can run the new viewshed 2 tool?

EzekielBaye1 — Wed, 09 Nov 2016 15:15:31 GMT

Thanks, I've tried both (geoid-based and spheroid/ellipsoid based). Neither works, just get the same error message.

Re: How do I add a vertical coordinate system to my raster so that I can run the new viewshed 2 tool?

XuguangWang — Wed, 09 Nov 2016 22:46:47 GMT

Just to clarify it a little, without a vertical coordinate system, the tool will still be able to run, just that it will assume the input raster's Z values and XY coordinate system are in the same unit.

So, if your raster's Z values and XY coordinate system are already in the same unit, you don't need a vertical coordinate system. You can ignore this message and still get a correct result from Viewshed 2.

If your raster's Z values are in a unit different from XY units (e.g., feet vs meters), and you don't want to use a vertical coordinate system, you must first convert the Z values into XY unit by applying a Z factor before using it in Viewshed 2 tool.