Swath Tool

Many vehicles have on-board sensors for observing or collecting data from areas on the Earth or equipment for communicating to and from points on the ground or other vehicles. To assist in the analysis of these sensor-vehicle systems, STK provides the ability to draw lines on the 2D and 3D Graphics windows that delineate the visible areas for the system, or the points on the ground from which the vehicle can be seen.

A sensor swath displays the area of coverage for the vehicle sensor. Swath lines are defined so that the inside of the swath is to the right when tracking along a line. Swath is not necessarily centered about the ground track.

Sensor swath is based on the evolution of the sensor footprint over time. Note that while the sensor footprint can be altered by the projection extension distance and by various field-of-view constraints, the swath footprint is based on the projection of the original unaltered sensor field-of-view to the ground.

The Swath tool is a sensor level tool available to sensors attached to any vehicle. To open the Swath tool, right-click the sensor in the Object Browser and select Swath... from the Sensor menu.

Select Swath to enable the display of the swath for the sensor. The following table defines the options available for the tool.

Option	Description
Color	The color of the line defining the boundaries of the swath in the 2D Graphics window.
Line/Marker Style	The style of the line defining the boundaries of the swath in the 2D Graphics window.
Line Width	The width of the line defining the boundaries of the swath in the 2D Graphics window.
Interval	Time period covered by swath graphics.
Start Time	Beginning and end of time period covered by swath graphics. For more information on the options available for intervals and start and stop times, see Time Options.
Stop Time
Computational Method	Select the Analytical or Numerical Computational Method for generating swaths. The Numerical Computational Method is not valid if the Sensor uses a Custom Pattern. The Analytical Computational Method is only valid if the parent of the Sensor is a Satellite and the Satellite has a Circular Orbit and the Satellite uses Nadir ECF Attitude and the Sensor is Nadir (Fixed) Pointing.
Minimum Step	The minimum step size for the adaptive step size of swath computation.
Maximum Step	The maximum step size for the adaptive step size of swath computation.
Use Maximum Cone	Select to perform swath computations based on the maximum cone that encompasses the sensor pattern instead of the actual pattern. In some cases - depending on the type of sensor and its pointing - this may result in a more informative swath with a superior appearance in the graphics windows. The sensor pattern will still be displayed normally; only its swath is affected by this option.
Advanced...	Scattering Tolerance - determines the angle with respect to the swath line within which candidate points are considered for possible connection to it. Curvature Tolerance - controls the adaptive step size of swath computation and ensures that neighboring samples adequately capture the curvature of the swath line.