# Creating a keyhole with the Keyhole (One Point - Azimuth) function (Aviation)

The Keyhole (One Point - Azimuth) function creates a polygon that is shaped like a keyhole based on one defined coordinate. The polygon is used to represent airspace.

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 Keyhole (One Point - Azimuth) 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 Radius and type a value for the radius in the selected cell.

This is the radius of the circular part of the airspace boundary and is relative to the first input coordinate (airport reference point). The default unit is Nautical Miles.

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.

7. Click the cell next to Azimuth and type the azimuth value.

The azimuth is the angle at which the keyhole is going to be created. This is the azimuth from the second input coordinate. The default value is degrees.

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 Azimuth Distance and type a value that represents the distance the angle should extend for the rectangular part of the keyhole.

This is the distance from the input coordinate to which the keyhole notch is going to extend. It must therefore be greater than the radius. The default unit is Nautical Miles.

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. Click the cell next to Left Buffer and type the value for the left buffer.

This is the width of the buffer to the left of the azimuth centerline. The default unit is Nautical Miles.

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 Right Buffer and type the value for the right buffer.

This is the width of the buffer to the right of the azimuth centerline. The default unit is Nautical Miles.

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.

11. 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.

12. 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.

13. 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.

14. 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.

15. Click the Execute button .

The keyhole geometry appears in the Scratch Data layer.

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

4/27/2014