Class AngularSeparationDetector

    • Constructor Detail

      • AngularSeparationDetector

        public AngularSeparationDetector​(PVCoordinatesProvider beacon,
                                         PVCoordinatesProvider observer,
                                         double proximityAngle)
        Build a new angular separation detector.
        Parameters:
        beacon - beacon at the center of the proximity zone
        observer - observer for the spacecraft, that may also see the beacon at the same time if they are too close to each other
        proximityAngle - proximity angle as seen from observer, at which events are triggered (rad)
      • AngularSeparationDetector

        protected AngularSeparationDetector​(AdaptableInterval maxCheck,
                                            double threshold,
                                            int maxIter,
                                            EventHandler handler,
                                            PVCoordinatesProvider beacon,
                                            PVCoordinatesProvider observer,
                                            double proximityAngle)
        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
        beacon - beacon at the center of the proximity zone
        observer - observer for the spacecraft, that may also see the beacon at the same time if they are too close to each other
        proximityAngle - proximity angle as seen from observer, at which events are triggered (rad)
    • Method Detail

      • create

        protected AngularSeparationDetector create​(AdaptableInterval newMaxCheck,
                                                   double newThreshold,
                                                   int newMaxIter,
                                                   EventHandler newHandler)
        Build a new instance.
        Specified by:
        create in class AbstractDetector<AngularSeparationDetector>
        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
      • getBeacon

        public PVCoordinatesProvider getBeacon()
        Get the beacon at the center of the proximity zone.
        Returns:
        beacon at the center of the proximity zone
      • getObserver

        public PVCoordinatesProvider getObserver()
        Get the observer for the spacecraft.
        Returns:
        observer for the spacecraft
      • getProximityAngle

        public double getProximityAngle()
        Get the proximity angle (rad).
        Returns:
        the proximity angle
      • g

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

        This function measures the angular separation between beacon and spacecraft as seen from the observer minus the proximity angle. It therefore triggers decreasing events when the spacecraft enters the proximity zone and increasing events when it leaves the proximity zone.

        No shadowing effect is taken into account, so this method is computed and may trigger events even when the spacecraft is below horizon for an observer which is a ground station. If such effects must be taken into account the detector must be associated with a predicate filter where the predicate function is based on elevation.

        Specified by:
        g in interface EventDetector
        Specified by:
        g in class AbstractDetector<AngularSeparationDetector>
        Parameters:
        s - the current state information: date, kinematics, attitude
        Returns:
        value of the switching function