Thiessen polygons extend outside of extent of projection

Question

I'm working on a geological project on the past position of continents (in ArcMap 10 Service Pack 5, build 4400). The tool I'm creating in Model Builder uses Create Thiessen Polygons and all input data are in Winkel-Tripel projection. The Create Thiessen Polygons tool however creates polygons that fall outside of the extent of the projection (see image), also when I specify the desired extent in the parameters of the CTP tool.

The result is that the Thiessen polygons (i.e. the shapefile) cannot be used by any other tools later on, because

the added layer has an extent that is not consistent with the associated spatial reference information

I've already tried clipping the Thiessen polygons shapefile, but not even that works (the Clip tool does not accept the Thiessen polygons as input, because of the inconsistent spatial reference).

Any suggestions on how to deal with this?

Answer 1

Sadly, Winkel-Tripel and other types of curved projections (like Robinson) are not optimal for doing GIS, especially at the scale you're working with, precisely due to this factor. Not only Thiessen polygons, but other types of geoprocessing that deal with area interpolation are bound to give off errors.

I see two options for you here:

1. as user17260 said, this is a limitation of the software, so you could try different softwares. That, however, will leave you without the ArcGIS tools (which, depending on the tool you may find a replicate in a different software, but you may also not).

2. reproject your data to a rectangular projection, and work on it this way. You'll be able to re-reproject it back later to Winkel-Tripel once you have your final products.

Answer 2

An Esri technical page on Error: One or more of the added layers has an extent not consistent with spatial reference says that the cause of this is:

When you add data to ArcMap, the software checks if the geographic coordinate system of the data falls within the range of -180 to 180 (longitude) and -90 to 90 (latitude). Any data that exceeds these values is considered to be erroneous.

This seems to be the case for your Thiessen polygons so it seems like you are dealing with a software limitation, and that your best way forward may be to submit a technical support incident to ask whether the developers of that software are aware of any workaround, or would consider relaxing the limitation.

Alternatively, you could first test using a later version, because 10.0 is now a retired version.

Another thought is whether you have tried removing the coordinate system from your feature class to make it undefined, and to Clip it with a polygon in another feature class which also has an undefined coordinate system. If that works you may be able to then apply the original coordinate sytem on data that falls precise on or inside the -180 to 180 (longitude) and -90 to 90 (latitude) limits.

Answer 3

Export your TIN to a feature class and "clip" the new feature class?