If you are using Esri’s ArcGIS GIS software program, there is a simple way to add coordinate information to the attribute table of a GIS data set.
Outlined in this article are the steps to take in order to add X Y coordinates to a field in the attribute table using Esri’s ArcGIS software. The tool used in ArcGIS to add coordinate values is called “Add XY Coordinates” and can be found in the ArcToolbox. (Related: How to Add Latitude and Longitude as a CSV File in QGIS)
What Are X and Y Coordinates?
X and Y coordinates are a pair of numbers, separated by a comma, that correspond to the position of a spatial feature on a horizontal and vertical axis. All geographic points are plotted as X and Y coordinates along two numbers that intersect at zero degrees X and Y to indicate where on the globe that feature exists. (Related: Geographic Coordinate System)
The X coordinate indicates how far east or west a point is long the x-axis. Negative values in an x coordinate is used to show that the point is located west of the Prime Meridian.
The Y coordinate indicates how far north or south a point is along the y-axis. Negative values in a y coordinate is used to indicate a geographic point is south of the Equator.
X and Y coordinates can be divided into four quadrants that reflect the areas of negative and positive values as shown in the diagram below.
The x value is known as the abscissa and the y value is known as the ordinate.
X and Y coordinates are listed as an ordered pair. This means that the first number is the X coordinate and the second number is the Y coordinate.
How to Add XY Coordinates to the Attributes for a GIS Dataset
First, load up an instance of ArcMap or ArcCatalog. From the toolbar, select the ArcToolbox icon to pull up the ArcToolbox window. This is the icon that has a red toolbox.
Next, navigate through the options in the ArcToolbox window. First click on the “+” sign to the left of the “Data Management Tools” to open up the options. Then click on the “+” sign to the left of the “Features” toolset. Finally, click on the “Add XY Coordinates” tool.
This will bring up the Add XY Coordinates window. If you are working in ArcMap and have the data layer already loaded, then select the layer from the drop down list. Otherwise, if you need to load the layer or are accessing the tool from ArcCatalog, then select the folder icon and navigate to the directory on your computer or server where the GIS dataset is stored. Then hit the “OK” button to start the process.
In the lower right hand corner of ArcMap or ArcCatalog, the status of the process will show. Depending on the size of your GIS data file, this process will take anywhere from a few seconds to a few minutes.
Once the process has run, you can examine the added information by right clicking on your data layer and selecting “Load Attributes” (if loaded into ArcMap) or by selecting the layer in ArcCatalog and clicking on the preview tab and then selecting “table” as the viewing option.
Appending to the last columns of your attribute field will be three fields: Point_X (containing the X coordinates), Point)_Y (containing the Y coordinates), and Point_Z (usually empty unless the data set is enabled with elevation (z) values).
This screenshot shows the XY table in ArcGIS.