# Creating an arc (Aviation)

The Arc (Azimuths) function creates an arc based on azimuths, which can be used as part of a more complex polygon geometry.

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 Arc (Azimuths) 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. Click the cell next to From Azimuth and type a value for the starting azimuth.

From Azimuth is the arc's starting azimuth relative to the centerpoint. Azimuth values are measured from north (0°). The default units is degrees.

7. 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.

8. Click the cell next to To Azimuth and type a value for the ending azimuth.

The To Azimuth is the arc's ending azimuth relative to the centerpoint. Azimuth values are measured from north (0°). The default unit is degrees.

9. 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.

10. Click the cell next to Radius and type the distance for the radius.

This is the radius for the arc, or the distance from the centerpoint to the arc's endpoints. The default unit is Nautical Miles.

11. 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.

12. If necessary, click the drop-down arrow next to Clockwise and choose False.

This indicates whether or not the arc is created in a clockwise direction. There are two options:

• True—The arc is created in a clockwise direction from the From Azimuth to the To Azimuth.
• False—The arc is created in a counterclockwise direction from the To Azimuth to the From Azimuth.
13. 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.

14. 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.

15. 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.

16. 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.

17. Click the Execute button .

An arc is created.

If the arc does not appear, click the Add Scratch Data Layers button at the top of the Feature Builder window.

4/27/2014