Class GeographicZoneDetector

  • All Implemented Interfaces:
    EventDetector

    public class GeographicZoneDetector
    extends AbstractDetector<GeographicZoneDetector>
    Detector for entry/exit of a zone defined by geographic boundaries.

    This detector identifies when a spacecraft crosses boundaries of general shapes defined on the surface of the globe. Typical shapes of interest can be countries, land masses or physical areas like the south atlantic anomaly. Shapes can be arbitrarily complicated: convex or non-convex, in one piece or several non-connected islands, they can include poles, they can have holes like the Caspian Sea (this would be a hole only if one is interested in land masses, of course). Complex shapes involve of course more computing time than simple shapes.

    Since:
    6.2
    Author:
    Luc Maisonobe
    See Also:
    FootprintOverlapDetector
    • Constructor Detail

      • GeographicZoneDetector

        public GeographicZoneDetector​(double maxCheck,
                                      double threshold,
                                      BodyShape body,
                                      SphericalPolygonsSet zone,
                                      double margin)
        Build a detector.
        Parameters:
        maxCheck - maximal checking interval (s)
        threshold - convergence threshold (s)
        body - body on which the geographic zone is defined
        zone - geographic zone to consider
        margin - angular margin to apply to the zone
      • GeographicZoneDetector

        protected GeographicZoneDetector​(AdaptableInterval maxCheck,
                                         double threshold,
                                         int maxIter,
                                         EventHandler handler,
                                         BodyShape body,
                                         SphericalPolygonsSet zone,
                                         EnclosingBall<Sphere2D,​S2Point> cap,
                                         double margin)
        Protected constructor with full parameters.

        This constructor is not public as users are expected to use the builder API with the various withXxx() methods to set up the instance in a readable manner without using a huge amount of parameters.

        Parameters:
        maxCheck - maximum checking interval
        threshold - convergence threshold (s)
        maxIter - maximum number of iterations in the event time search
        handler - event handler to call at event occurrences
        body - body on which the geographic zone is defined
        zone - geographic zone to consider
        cap - spherical cap surrounding the zone
        margin - angular margin to apply to the zone
    • Method Detail

      • create

        protected GeographicZoneDetector create​(AdaptableInterval newMaxCheck,
                                                double newThreshold,
                                                int newMaxIter,
                                                EventHandler newHandler)
        Build a new instance.
        Specified by:
        create in class AbstractDetector<GeographicZoneDetector>
        Parameters:
        newMaxCheck - maximum checking interval (s)
        newThreshold - convergence threshold (s)
        newMaxIter - maximum number of iterations in the event time search
        newHandler - event handler to call at event occurrences
        Returns:
        a new instance of the appropriate sub-type
      • withMargin

        public GeographicZoneDetector withMargin​(double newMargin)
        Setup the detector margin.
        Parameters:
        newMargin - angular margin to apply to the zone
        Returns:
        a new detector with updated configuration (the instance is not changed)
      • getBody

        public BodyShape getBody()
        Get the body on which the geographic zone is defined.
        Returns:
        body on which the geographic zone is defined
      • getZone

        public SphericalPolygonsSet getZone()
        Get the geographic zone.
        Returns:
        the geographic zone
      • getMargin

        public double getMargin()
        Get the angular margin to apply (radians).
        Returns:
        the angular margin to apply (radians)
      • g

        public double g​(SpacecraftState s)
        Compute the value of the detection function.

        The value is the signed distance to boundary, minus the margin. It is positive if the spacecraft is outside of the zone and negative if it is inside.

        Specified by:
        g in interface EventDetector
        Specified by:
        g in class AbstractDetector<GeographicZoneDetector>
        Parameters:
        s - the current state information: date, kinematics, attitude
        Returns:
        signed distance to boundary minus the margin