I need to convert points from either State Plane or WGS84 to Lot/Long, is there an easy way to do so? Thank you very much.

I need to convert points from either State Plane or WGS84 to Lot/Long, is there an easy way to do so? Thank you very much.

Melita,

I have an Excel spreadsheet with Lat Long in WGS84. I want to add the points in ArcMap and then export a shapefile converted to State Plane NAD83. Do you have a workflow you can suggest, and do you know if this has been done in Model Builder?

Hi,

I haven't, but I use modelbuilder very infrequently. It looks like the first step would be to use this tool:

Make XY Event Layer

To do it in ArcMap (or ArcCatalog):

Adding x,y coordinate data as a layer

which includes how to export to a shapefile. One thing to remember in v10 is that the Add XY Data dialog will default the coordinate system to what the data frame's using. If you definitely want to add the data as WGS84, change the coordinate system in the dialog.

To convert to NAD83, you can do several things. If the data's accuracy is around a meter, you can assume they're the same and either directly define the data as NAD83 or use a transformation like NAD_1983_To_WGS_1984_1 (which has zeroes for the parameter values). If the accuracy is better, I would use NAD_1983_To_WGS_1984_5.

Melita- 1 person found this helpful
If you have the points in a spreadsheet already .... Batch Convert

or use an excel addin GeogTools | DimensionEngine

- 1 person found this helpful
For adding lat/long values as attributes, I would map your features using the X,Y event option previously mentioned. Next, add two new fields to the table for your lat/long values. Finally, use the Calculate Geometry option to populate the field with the lat/long values.

Latitude/longitude are decimal degrees values based on a particular geographic coordinate system (datum). WGS 1984 is a geographic coordinate system. State Plane coordinates can be based upon NAD 1927, NAD 1983, NAD 1983 HARN, etc. That is, one of several geographic coordinate systems. For any points you want to convert, you'll need to know exactly what the current coordinate system is. ArcGIS doesn't support converting values in a file, or a table. You can put the points into an Excel worksheet, or text file, or comma-separated values in a file like:

ID,X,Y

1,2439393.908,534392.447

Use the Add XY Data tool in ArcMap to add the data. When using the tool, set the coordinate system. Once the data's in ArcMap, change ArcMap's coordinate system to the output coordinate system that you want. Right click the layer in the table of contents and choose Data, Export Data. In this dialog, set it to use the data frame's coordinate system and write out the data as a shapefile or a feature class.

Melita