Package org.orekit.propagation.events

Class EclipseDetector

java.lang.Object
org.orekit.propagation.events.AbstractDetector<EclipseDetector>
org.orekit.propagation.events.EclipseDetector
All Implemented Interfaces:
EventDetector
public class EclipseDetector extends AbstractDetector<EclipseDetector>
Finder for satellite eclipse related events.

This class finds eclipse events, i.e. satellite within umbra (total eclipse) or penumbra (partial eclipse).

The occulted body is given through a PVCoordinatesProvider and its radius in meters. It is modeled as a sphere.

Since v10.0 the occulting body is a OneAxisEllipsoid, before it was modeled as a sphere.
It was changed to precisely model Solar eclipses by the Earth, especially for Low Earth Orbits.
If you want eclipses by a spherical occulting body, set its flattening to 0. when defining its OneAxisEllipsoid model..

The withUmbra() or withPenumbra() methods will tell you if the event is triggered when complete umbra/lighting is achieved or when entering/living the penumbra zone.
The default behavior is detecting complete umbra/lighting events.
If you want to have both, you'll need to set up two distinct detectors.

The default implementation behavior is to continue propagation when entering the eclipse and to stop propagation when exiting the eclipse.
This can be changed by calling AbstractDetector.withHandler(EventHandler) after construction.

Author:
Pascal Parraud, Luc Maisonobe
See Also:

  • Constructor Details

    • EclipseDetector

      public EclipseDetector(ExtendedPositionProvider occulted, double occultedRadius, OneAxisEllipsoid occulting)
      Build a new eclipse detector.

      The new instance is a total eclipse (umbra) detector with default values for maximal checking interval (AbstractDetector.DEFAULT_MAX_CHECK) and convergence threshold (AbstractDetector.DEFAULT_THRESHOLD).

      Parameters:
      occulted - the body to be occulted
      occultedRadius - the radius of the body to be occulted (m)
      occulting - the occulting body
      Since:
      12.0

    • EclipseDetector

      public EclipseDetector(OccultationEngine occultationEngine)
      Build a new eclipse detector.

      The new instance is a total eclipse (umbra) detector with default values for maximal checking interval (AbstractDetector.DEFAULT_MAX_CHECK) and convergence threshold (AbstractDetector.DEFAULT_THRESHOLD).

      Parameters:
      occultationEngine - occultation engine
      Since:
      12.0

    • EclipseDetector

      protected EclipseDetector(EventDetectionSettings detectionSettings, EventHandler handler, OccultationEngine occultationEngine, double margin, boolean totalEclipse)
      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:
      detectionSettings - detection settings
      handler - event handler to call at event occurrences
      occultationEngine - occultation engine
      margin - to apply to eclipse angle (rad)
      totalEclipse - umbra (true) or penumbra (false) detection flag
      Since:
      12.2

  • Method Details

    • create

      protected EclipseDetector create(EventDetectionSettings detectionSettings, EventHandler newHandler)
      Build a new instance.
      Specified by:
      create in class AbstractDetector<EclipseDetector>
      Parameters:
      detectionSettings - detection settings
      newHandler - event handler to call at event occurrences
      Returns:
      a new instance of the appropriate sub-type

    • withUmbra

      public EclipseDetector withUmbra()
      Setup the detector to full umbra detection.

      This will override a penumbra/umbra flag if it has been configured previously.

      Returns:
      a new detector with updated configuration (the instance is not changed)
      Since:
      6.1
      See Also:

    • withPenumbra

      public EclipseDetector withPenumbra()
      Setup the detector to penumbra detection.

      This will override a penumbra/umbra flag if it has been configured previously.

      Returns:
      a new detector with updated configuration (the instance is not changed)
      Since:
      6.1
      See Also:

    • withMargin

      public EclipseDetector withMargin(double newMargin)
      Setup a margin to angle detection.

      A positive margin implies eclipses are "larger" hence entry occurs earlier and exit occurs later than a detector with 0 margin.

      Parameters:
      newMargin - angular margin to apply to eclipse detection (rad)
      Returns:
      a new detector with updated configuration (the instance is not changed)
      Since:
      12.0

    • getMargin

      public double getMargin()
      Get the angular margin used for eclipse detection.
      Returns:
      angular margin used for eclipse detection (rad)
      Since:
      12.0

    • getOccultationEngine

      public OccultationEngine getOccultationEngine()
      Get the occultation engine.
      Returns:
      occultation engine
      Since:
      12.0

    • getTotalEclipse

      public boolean getTotalEclipse()
      Get the total eclipse detection flag.
      Returns:
      the total eclipse detection flag (true for umbra events detection, false for penumbra events detection)

    • g

      public double g(SpacecraftState s)
      Description copied from interface: EventDetector
      Compute the value of the switching function. This function must be continuous (at least in its roots neighborhood), as the integrator will need to find its roots to locate the events.
      Parameters:
      s - the current state information: date, kinematics, attitude
      Returns:
      value of the switching function