TargetLineOfSightOperator: which targets can I see?
Suppose we know the positions of some targets, and wonder if our observer can see them. For ground-based targets, we can display the targets on the map and see whether they are inside the viewshed surface for the ground. But for airborne targets, it is not so easy to use the viewshed surface or the viewshed volume.
A specific operator, TargetLineOfSightOperator, can answer the question directly. It has an additional input, targetInput, which gives the target positions. The output consists of the target positions with extra attributes, which tell how many observers can see the target, and also the names of the seeing observers.
The TargetLineOfSightOperator can also output the lines of sight between observers and targets. If there are many observers and many targets, showing all lines of sight can be messy. But the LineVisualizer can be placed in the VisualizationOperator.SelectionVisualizers, which means that the lines of sight to each target are shown only when the target is selected.
If the observer expects airborne targets, but we do not have their positions, we cannot use a TargetLineOfSightOperator. Instead, we can use an ordinary LineOfSightOperator and assume a minimal target height above ground; see LineOfSightOperator: What can I see?.
For a TargetLineOfSightOperator, we recommend not retrieving elevation data in Multiple Resolution. (It is possible to do so, but the performance is usually not improved.)
Previous: AirspaceCoverageOperator: What can we see together?
Up: Visibility Analysis
Next: VisibilityIndexOperator: from where do I see best?