# Calculating a bearing distance (Aviation)

The Bearing Distance Calculator function calculates the forward and backward azimuths between two specified coordinates as well as the distance. This can be used to place features so they are relative to one another.

1. Start ArcMap.
2. On the menu bar, click Customize > Toolbars > Production Feature Builder.
3. Click the Feature Builder button on the Production Feature Builder toolbar.

The Feature Builder window appears.

提示:

The Feature Builder window can be placed anywhere in ArcMap, or in the Table Of Contents window, with the aid of the arrows showing the possible placement positions.

4. Choose Bearing Distance Calculator in the list on the Functions tab.

5. Define a coordinate for the start point of the polyline by doing one of the following:
• Clicking the Pinprick tool on the Production Feature Builder toolbar, then clicking on the map
• Typing the coordinates in the cells on the Input tab in the Coordinates area
提示:

To view the input coordinates on the map, double-click the row headers for each coordinate.

6. Repeat step 5 to define a coordinate for the ending point of the inverse method.
7. If necessary, click the cell next to MagVar Value and type a value for the magnetic variation.

This can be a specified value or from a field defined in the MagVar Source parameter. The default unit is degrees.

8. 提示:

You can right-click the parameter name and change the unit of measurement. If you change the unit of measurement after defining a value, the value is converted to the new unit of measurement, and you may need to redefine the value.

9. If necessary, click the drop-down arrow next to MagVar Source and choose a source for the magnetic variation.

This is the source of the magnetic variation value.

10. If necessary, click the drop-down arrow next to MagVar Year and choose a different year for the World Magnetic Model.

This is the year associated with the magnetic variation value.

注:

You can only choose a value for MagVar Year if Magnetic Model is selected for the MagVar Source property.

11. Click the Execute button .
12. Click the Output tab in the Functions area.

Values are populated for the Forward Azimuth, Back Azimuth, and Distance parameters. Forward Azimuth is the angle from the first coordinate to the second coordinate. Back Azimuth is the angle from the second coordinate to the first coordinate. The Distance value represents the distance between the first and second coordinate.

You can right-click the parameter name and change the unit of measurement. If you change the unit of measurement after defining a value, the value is converted to the new unit of measurement, and you may need to redefine the value.

4/27/2014