Creating Shapefile from Excel Data

Question

I have an Excel file with three columns, IncidentID, Latitude, and Longitude. Each row in the file corresponds to an incident and the location of the incident in units of decimal degrees.

I also have a road shapefile of the area in which these incidents occurred. The road shapefile has the WGS_1984_UTM_Zone_42N Projected Coordinate System and GCS_WGS_1984 Geographic Coordinate System and whose whose units (as far as I can tell) are in meters.

I can use 'Add Data' to add the excel file, and then use 'Display XY Data' to import the data, but the import interprets the Latitude and Longitude values as meter values. How do I tell ArcGIS to interpret the Latitude and Longitude values as decimal degree values?

Answer 1

When you Display X/Y Data, setting the Coordinate System to GCS_WGS_1984 should give you values in decimal degrees.

• derNincompoop: Turns out I had my Longitude and Latitude mixed up. Your answer worked for me when I fixed that. Thanks.

Answer 2

Import the Excel data into either a blank (new) data frame, and it should set it to decimal degrees automatically. Right now, it's inheriting the units of your current data frame, which are set to meters because of the road shapefile.

Once you've imported it as decimal degrees, you can export to a new shapefile or feature class and transform the projection to whatever you need (e.g. UTM 42N).

• derNincompoop: I opened a blank (new) map document (in ArcMap). I then used 'Add Data' to add the excel file. When I used 'Display XY Data' to import the data, the 'Coordinate System of Input Coordinates' only displays 'Unknown Coordinate System'. It does not detect decimal degrees automatically. Any thoughts?
• Erica: There should be an Edit button near that dialog which will open the Spatial Reference Properties dialog, and there you can set it to WGS84. Instructions for that are at Esri's HowTo: Import XY data tables to ArcMap and convert the data to a shapefile