topic Re: shapefile won't project in ArcGIS Pro Questions

shapefile won't project

AnnDeutch — Wed, 31 Jan 2024 18:26:13 GMT

I was given a shapefile without xy coordinates in the attribute table. WGS 1984. It projected properly before, but not now. I added x_proj and y_proj fields, calculated geometry and the lat-long degrees were correct. But it still displays in the wrong place/wrong scale. What else can I do?

Re: shapefile won't project

Margaret_M_Maher — Wed, 31 Jan 2024 18:40:18 GMT

Please check Knowledge article 000007880 at the link below. This article plus the articles which are attached to it will help you detemine the coordinate system for the input data. The projection for the data must be defined correctly or the Project tool will not work to create a new set of data in the desired output projection. Post again if you have further questions.

https://support.esri.com/en-us/knowledge-base/how-to-identify-the-spatial-reference-projection-or-coo-000007880

Re: shapefile won't project

DanPatterson — Wed, 31 Jan 2024 18:40:22 GMT

details of what you got would be useful

There is a chance that it was "defined" incorrectly at some stage.

If that is the case use

Define Projection (Data Management)—ArcGIS Pro | Documentation

to get set the correct coordinate system, then use

Project (Data Management)—ArcGIS Pro | Documentation

Projecting a file that is defined incorrectly will never get the coordinates right.

Re: shapefile won't project

AnnDeutch — Wed, 31 Jan 2024 20:15:59 GMT

ArcGIS pro, recently updated. I was told by the provider that this would work as WGS1984. I opened a new project/map in WGS 1984, added data with a new copy of the original shapefile. Properties:

The lat-long matches my location. I used Define Projection:

Still no improvement. It displays on the map as a tiny figure at 0 degrees. I hope you can help further.

Re: shapefile won't project

AnnDeutch — Wed, 31 Jan 2024 20:21:08 GMT

PS: This time I did not add new fields for x_proj or y_proj. I used a clean unchanged copy of the originally provided shapefile. For what that's worth..... Ann

Re: shapefile won't project

AnnDeutch — Wed, 31 Jan 2024 21:17:07 GMT

Dan I read Margaret's instructions and the links she provided. Then I followed your instructions.

ArcGIS pro, recently updated. I was told by the provider that this would work as WGS1984. I opened a new project/map in WGS 1984, added data with a new copy of the original shapefile. Properties:

The lat-long matches my location. I used Define Projection:

Still no improvement. It displays on the map as a tiny figure at 0 degrees. I hope you can help further. I also tried reducing the extent of my map to my local area then adding the shapefile. No luck.

Ann ----- also retired, this is a volunteer bathymetry project for my HOA.

Re: shapefile won't project

DanPatterson — Wed, 31 Jan 2024 21:45:02 GMT

If the geometry fields calculated from the geometry field were in decimal degrees, it should have been defined as a geographic coordinate system with the WGS84 datum. It could then be projected to what appears to be web mercator (WGS 1984 Web Mercator (auxilary sphere)).

Let's make sure that WGS84 (which is a datum, not a coordinate system) is being used as a datum and it wasn't inadvertantly defined... which would put the shapefile near the 0 lat, 0 long

Re: shapefile won't project

Margaret_M_Maher — Wed, 31 Jan 2024 21:46:27 GMT

Hello Ann, Margaret here again. Please open article 000007880. and check out the diagram showing the distribution of geographci (decimal degree) coordinates across the earth's surface. Degrees are angles, and there are 360 degees in a circle. Your coordinates at 39 and -86, so if you look at that diagram you see those values place that data in the United States. Y is positive becaise you are north of the Equator and the X's are negative because you are west of Greenwich, England. Remember graphing in Algebra, upper right quadrant X is positivem Y is positive, upper left quadrant, Y is positive, X is negative. So based on the size of those numbers those coordinates are in decimal degrees, so that is a Geographic Coordinate Ssytem, GCS_WGS_1984. If you look at the parameters for WGS 1984 Web Mercator, the units are METERS, NOT degrees. I know it's ON GCS_WGS-1984 but that is just the definition for the shape and size of the earth those coordinates are on. If you want the data in Web Mercator, you have to define the projection FIRST as what it is, which is the Geographic Coordinate System GCS_WGS_1984, THEN you can project it to Web Mercator. Pign me again if it's still not working for you!

Re: shapefile won't project

AnnDeutch — Wed, 31 Jan 2024 22:37:42 GMT

Thank you. As a self-taught user, I was confused about geographic versus projection even after reading your linked article and lots of other help files. Your explanation finally made it all click for me. Ann

Re: shapefile won't project

Margaret_M_Maher — Wed, 31 Jan 2024 23:05:58 GMT

Ann, you need to define the projection from the folder labeled Geographic coordinate ssytems > World > WGS 1984.

After you have defined the projection, check to make sure that data draws in the correct locatoin in ArcGIS Pro. If you to not define the projection correctly the data will draw in the wrong place.

verifuing that the data is drawing in the correct place means that the projetis DEFINED correctly.

Now, open the Project tool from ArcToolbox. Select that layer as the itnput. Select the location where you want to write out the NEW copy of the data in the different projection and give it a name.

In the Output Coordinate system box, open the browse button and open Projected Coordinate Systems. Geographic Coordinate Systems have units that are angles - decimal degrees. A Projected Coordinate System has linear units that you can measure with a ruler. Mercator is a Projected Coordinate Sstem that has units of meters. You want that projection for your output. So open Projected Coordinate Systems > World. Scroll down and select WGS 1984 Web Mercator Auxiliary Sphere. Click Ok, and run the tool. The new copy of the file will open in Pro in your map and will also draw in the correct place.

Now go back and right click on the original data > Properties > and look again at the extent numbers. Now they are labeled as Deg for degrees and they are very small numbers.

Close that dialog and right click the new copy of the data that you projected to Web Mercator. Go to Properties > and look at teh extent values for the new layer. Those numbers are huge. That is the difference between a Geographic Coordinate System and a Projected Coordinate System.

Let me know if you have further problems. Projections are hard!