Package org.orekit.propagation.events

Class ApsideDetector

  • All Implemented Interfaces:
    EventDetector
    public class ApsideDetector
extends AbstractDetector<ApsideDetector>
    Finder for apside crossing events.

    This class finds apside crossing events (i.e. apogee or perigee crossing).

    The default implementation behavior is to continue propagation at apogee crossing and to stop propagation at perigee crossing. This can be changed by calling AbstractDetector.withHandler(EventHandler) after construction.

    Beware that apside detection will fail for almost circular orbits. If for example an apside detector is used to trigger an ImpulseManeuver and the maneuver change the orbit shape to circular, then the detector may completely fail just after the maneuver has been performed!

    Author:
    Luc Maisonobe
    See Also:
    Propagator.addEventDetector(EventDetector)

    • Constructor Detail

      • ApsideDetector

        public ApsideDetector​(double keplerianPeriod)
        Build a new instance.

        The Keplerian period is used only to set an upper bound for the max check interval to period/3 and to set the convergence threshold.

        Parameters:
        keplerianPeriod - estimate of the Keplerian period
        Since:
        12.1

      • ApsideDetector

        public ApsideDetector​(Orbit orbit)
        Build a new instance.

        The orbit is used only to set an upper bound for the max check interval to period/3 and to set the convergence threshold according to orbit size

        Parameters:
        orbit - initial orbit

      • ApsideDetector

        public ApsideDetector​(double threshold,
                      Orbit orbit)
        Build a new instance.

        The orbit is used only to set an upper bound for the max check interval to period/3

        Parameters:
        threshold - convergence threshold (s)
        orbit - initial orbit

      • ApsideDetector

        public ApsideDetector​(EventDetectionSettings detectionSettings,
                      EventHandler handler)
        Public constructor with full parameters.

        This constructor is public because otherwise all accessible ones would require an orbit.

        Parameters:
        detectionSettings - detection settings
        handler - event handler to call at event occurrences
        Since:
        13.0

    • Method Detail

      • g

        public double g​(SpacecraftState s)
        Compute the value of the switching function. This function computes the dot product of the 2 vectors : position.velocity.
        Parameters:
        s - the current state information: date, kinematics, attitude
        Returns:
        value of the switching function