Sensor Projection
2D Projection Graphics for sensors control the display of sensor projection graphics in the 2D Graphics window. Sensors attached to facilities/places/targets differ in their display behavior from those attached to vehicles. The intersections of vehicle-based sensors with the Earth are displayed during animation.
You can display non-targeted sensors attached to facilities/places/targets projected at:
- A set of altitudes
- A set of ranges from the parent object to the facility/place/target
- The altitude of a specified vehicle
- The range specified by the range constraint
Sensor Projection Options
| Option | Value |
|---|---|
| Show Intersections | Specifies one of the following:
Central body. Modifies the field of view of the sensor to account for its intersections with the central body. Terrain. Modifies the field of view of the sensor to account for its intersections with the central body and terrain. The requested terrain intersection region is defined by its North, South, East and West boundaries. The actual extent of the terrain intersection region depends on the availability of terrain and the type of the terrain source. This option is only available for sensors located on vehicles. The region of loaded terrain may actually be larger than the specified region depending on the type of terrain source used and the possible sharing of terrain data from multiple sensors showing terrain intersections in the same region. None. Does not modify the field of view of the sensor by ignoring any possible intersections. It can be used, for example, if you want to use the sensor to help detect obscuration by the spacecraft body and want to avoid the removal of parts of the outer sensor cone that would ordinarily result from intersections with the Earth. |
| Show Projection on 2D Map | Displays the sensor projection in the 2D Graphics window. |
| Persistence Time | The length of time the sensor's footprint remains visible during animation. It is used to display sensor footprints for a specified period of time so that you can determine quickly and easily whether coverage requirements are being met. |
| Persist in Forward Animation Direction Only | Displays the sensor's footprints when animating in the forward direction only. |
| Fill Persistence | Displays the sensor's footprints as filled areas on the surface of the central body if the Fill option is also enabled on the 2D Graphics Attributes page. |
| Display Times affects Persistence |
When enabled, the display of the sensor persistent footprints depend on the sensor's display times. If disabled (default), persistent footprints will continue to be displayed even when the sensor projection is not displayed due to the sensor's display times. The parent object's display times (if it has any) do not affect persistence. If the parent object's graphics are turned off, the child object's graphics are also turned off. The browser on/off indicator turns off all sensor graphics, including sensor persistence. |
| Field of View Use Constraints |
If checked, defines which constraints can be used to modify the field of view of the sensor. Use this option to evaluate the effect of various constraints on visibility along all possible lines of sight within the field of view.
To use a particular constraint to constrain the field of view of a sensor, it must be enabled on the Constraints Property page for that sensor. |
| Extension Distances Use | Indicates whether the sensor’s field-of-view crossings at specified distances are computed and displayed in the 2D Graphics window. |
| Project to: | Projects the sensor to one of the following:
Constant Altitude. Projects the sensor to one or more altitudes above the facility/place/target, measured along the normal to the surface of the parent. Constant Range from Parent Object. Projects the sensor to one or more ranges from the parent facility, place or target. Object Altitude. Projects the sensor to the altitude of a selected vehicle. Use Range Constraint. Projects the sensor to the range constraint specified on the Basic Constraints properties page for the facility, place or target. If range constraint is not enabled, the Constant Range From Parent Object is used instead. |
| Projection Altitude Min/Max Altitude | Specifies one or more altitudes above the facility, place or target from which the sensor projects. |
| Projection Range Min/Max Range | Specifies one or more ranges from the parent facility, place or target from which the sensor projects. |
| Step Count |
Determines the interval between sensor projections.
For a specified min/max altitude: the step count determines the number and altitude of projections to be displayed. Each projection is computed as the intersection of the sensor pattern with a sphere at the requested altitude. This intersection is then mapped back to the surface of the Earth for display. For example, a sensor with Minimum/Maximum Altitude settings of 500 km and 1000 km and a Step Count of 3 would display projections at altitudes of 500 km, 750 km and 1000 km. For a specified min/max range: the step count is used to determine the number of projections to display and the range value for each projection. Each value is used to project the sensor to the given range from the parent facility, place or target. This projection is then mapped back to the surface of the Earth for display. |
| Projection Altitude Object | Projects the sensor to the altitude of the selected vehicle.
Only one object can be highlighted in the Projection Altitude Object list. |
| Project Through Crossing | Indicates whether the sensor’s field-of-view will extend beyond specified crossings. |
| Exclude Horizon Arcs | Specifies whether to exclude the lines that indicate the intersection of the sensor with the horizon. |
| Altitude Crossing Sides |
Indicates the crossings that are computed and displayed in the 2D Graphics window:
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| Direction | Indicates the direction in which the sensor’s field of view crosses the specified altitude:
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