topic Re: Coordinate System Transformation in ArcMap Questions

Coordinate System Transformation

AlexandraVoight — Mon, 29 Mar 2021 18:15:57 GMT

Hello,

I have 2 layers. Layer 1 has Geographic Coordinate System: WGS 84 and Datum: WGS_1984. Layer 2 has Geographic Coordinate System: WGS_1984 and datum WGS_1984. In order to clip these layers, apparently they need to have the same coordinate system. So, I used the "Projections and Transformations" tool in the ArcToolbox to transform the 1st layer's coordinates to WGS_1984. There is a drop down list that you can choose which Geographic Transformation you would like to apply. When I click on the drop down, it provides no options for transformations. If I skip this step and press "OK," the transformation to WGS_1984 fails with the following errors (screenshot attached). What do I need to do to make this transformation so I can finally clip the layers?

Re: Coordinate System Transformation

JayantaPoddar — Mon, 29 Mar 2021 18:36:14 GMT

Something looks off in the coordinate system of the input data. Since both the layers' datum are same, there shouldn't be a need for a transformation method.

Could you share the input datasets (sample), so that we could have a look at it?

Re: Coordinate System Transformation

AlexandraVoight — Mon, 29 Mar 2021 18:40:33 GMT

Thanks for taking a look at this! Unfortunately I can't share the first dataset due to company policy, but attached are its properties. Does that help?

Re: Coordinate System Transformation

JayantaPoddar — Mon, 29 Mar 2021 18:49:14 GMT

Could you save (Export Data) the layers as a shapefile or FGDB Feature Class, and then run the Project/Clip tool?

Re: Coordinate System Transformation

AlexandraVoight — Mon, 29 Mar 2021 19:00:51 GMT

Hmmm I'm trying to do this, but I get an error saying "output name is not valid."

Re: Coordinate System Transformation

JayantaPoddar — Mon, 29 Mar 2021 19:04:14 GMT

What's the full path of your output? Try saving it in your local drive without any space or special characters, and keep the path short. e.g. C:\MyData\layer1.shp

Re: Coordinate System Transformation

AlexandraVoight — Tue, 30 Mar 2021 00:49:30 GMT

Great. Working on that. Unfortunately running into another error with this step as well. I just chose to upgrade ArcGIS desktop to the newest version (I had 10.4.1) so hopefully that helps. However, it's been installing for 3 hours and is only 10% complete. Do you have an idea for why the slow installation? Today is apparently not my day.

Re: Coordinate System Transformation

JayantaPoddar — Tue, 30 Mar 2021 01:45:39 GMT

That's pretty slow. Please ensure all other applications are closed. Any Windows update at the background may also take up a big chunk of memory.

Re: Coordinate System Transformation

curtvprice — Fri, 02 Apr 2021 14:04:04 GMT

It sounds like to me like they are the same coordinate system, just the labeling is different. This sometimes happens with datasets created from different software or versions of software.

If they really are the same, you can use the Define Projection tool to define them both to WGS 1984 (to find it in the dialog search for 4326). May want to work on a copy if you are not sure about this.