Attitude Coverage Grid Constraint Options

The grid point definition defines the properties of the object pointing, which depends on the directions represented by points on the coverage grid. That object must be a sensor, transmitter, receiver or radar whose parent object is the one for which Attitude Coverage is being defined. The basic properties of that object (such as a sensor's field of view), including its position at each time step in the coverage interval, as well as any constraints imposed on it, help determine its access or lack thereof to the selected assets. Similarly, these properties are taken into account in Figure Of Merit computations.

To specify an object whose properties can be used in determining access to the selected assets, or in Figure Of Merit calculations, click Grid Constraint Options on the Attitude Coverage's Basic Grid properties page and set the following options.

Option	Description
Use Object Instance for Constraints	To assign additional access constraints to the grid points, select Use Object Instance for Constraints and select an Object Class. All available objects of that type are displayed. Select an object from the list.
Use Actual Object on the Grid Points	If you select Use Actual Object on the Grid Points, the actual object in the scenario that you selected will be used in coverage computations. If not selected, a copy is used. Using the actual object speeds up coverage computations but may result in unexpected and undesired changes to the object. Using a copy prevents such consequences, but can slow down computations. If you are defining coverage using a sensor as an asset, and that sensor is targeted to the grid point object, you must select Use Actual Object on the Grid Points to ensure that the sensor targeting is updated for each grid point. This also applies to objects attached to such targeted sensors.
Use Selected Vector	Defines the relationship between the object pointing and a grid point direction. If Use Selected Vector is not selected, the object's boresight is assumed pointed along a grid point direction using the azimuth and elevation pointing method with the Rotate option. If a particular vector is selected, the vector is pointed along the grid point direction and the object's pointing is affected through its dependency on this vector. The original pointing of the vector is restored after Attitude Coverage computations are completed. Only vectors that are defined as Fixed in Axes and use the same Reference Axes listed on the Grid Definition properties page for AttitudeCoverage are available for selection. If the Select Vector list is empty, launch the Vector Geometry Tool to define a Fixed in Axes vector or change the reference axes listed on the Grid Definition properties page for AttitudeCoverage.

Option

Description

Use Object Instance for Constraints

To assign additional access constraints to the grid points, select Use Object Instance for Constraints and select an Object Class. All available objects of that type are displayed. Select an object from the list.

Use Actual Object on the Grid Points

If you select Use Actual Object on the Grid Points, the actual object in the scenario that you selected will be used in coverage computations. If not selected, a copy is used. Using the actual object speeds up coverage computations but may result in unexpected and undesired changes to the object. Using a copy prevents such consequences, but can slow down computations.

If you are defining coverage using a sensor as an asset, and that sensor is targeted to the grid point object, you must select Use Actual Object on the Grid Points to ensure that the sensor targeting is updated for each grid point. This also applies to objects attached to such targeted sensors.

Use Selected Vector

Defines the relationship between the object pointing and a grid point direction.

If Use Selected Vector is not selected, the object's boresight is assumed pointed along a grid point direction using the azimuth and elevation pointing method with the Rotate option.

If a particular vector is selected, the vector is pointed along the grid point direction and the object's pointing is affected through its dependency on this vector. The original pointing of the vector is restored after Attitude Coverage computations are completed.

Only vectors that are defined as Fixed in Axes and use the same Reference Axes listed on the Grid Definition properties page for AttitudeCoverage are available for selection. If the Select Vector list is empty, launch the Vector Geometry Tool to define a Fixed in Axes vector or change the reference axes listed on the Grid Definition properties page for AttitudeCoverage.