Package org.orekit.propagation.events
EventDetector
instances are registered to any Propagator
. When the event associated with the detector occurs, the propagator interrupts
the propagation and calls the eventOccurred
method of the event handler, which can do whatever the user want and either stop or resume
propagation, optionally resetting the state.
If the registered events detectors are configured to stop propagation when triggered, the propagator can be run with an arbitrary large target date, relying on the events occurrence to stop propagation exactly at the right time.
The package provides some predefined events:
AlignmentDetector
detects satellite/body alignment (and by default stop when reaching alignment)AngularSeparationDetector
detects angular separation thresholds crossing between spacecraft and a beacon (typically the Sun) as seen from an observer (typically a ground station)AltitudeDetector
detects altitude crossing (and by default stop at descending)ApsideDetector
detects apside crossing (and by default stop at perigee)DateDetector
detects occurrence of a predefine instant (and by default stop there)EclipseDetector
detects satellite entering/exiting an eclipse (and by default stop on exit)ElevationDetector
detects satellite raising/setting (and by default stop at setting)ElevationExtremumDetector
detects satellite maximum/minimum elevation (and by default stop at minimum)FieldOfViewDetector
detects moving target entering/exiting satellite sensor Field Of View with an arbitrarily shaped boundary (and by default continue on entry and stop on exit)FootprintOverlapDetector
detects geographic zone entering or exiting Field Of View of a spacecraft sensor (and by default stop at zone exit)GeographicZoneDetector
detects geographic boundaries crossings (and by default stop at zone exit)GroundFieldOfViewDetector
detects spacecraft entering/exiting ground based Field Of View with an arbitrarily shaped boundary (and by default continue on entry and stop on exit)LatitudeCrossingDetector
detects satellite crossing a parallel (and by default stop at northward crossing)LatitudeRangeCrossingDetector
detects satellite crossing a parallel range (and by default stop exiting range)LatitudeExtremumDetector
detects satellite maximum/minimum latitude (and by default stop at minimum)LongitudeCrossingDetector
detects satellite crossing a meridian (the increasing/decreasing flag is irrelevant for this detector)LongitudeRangeCrossingDetector
detects satellite crossing a meridian range (and by default stop exiting range)LongitudeExtremumDetector
detects satellite maximum/minimum longitude (and by default stop at minimum)NodeDetector
detects node crossing (and by default stop at ascending node)PositionAngleDetector
detects anomaly, latitude argument or longitude argument crossings, with either true eccentric or mean angles (the increasing/decreasing flag is irrelevant for this detector)
In addition to raw events, the class also provides EventsLogger
to gather all events that occurred during a propagation, EventShifter
which allows to slightly shift an
event in time (for example to trigger something say 5 minutes before eclipse entry), EventSlopeFilter
and EventEnablingPredicateFilter
to trigger
only specific types of events, without losing computation time by locating events user is not
interested in. Also the BooleanDetector
allows
the user to combine other event detectors using Boolean logic.
The low level interfaces and classes are heavily based on similar classes from the ode.events package from the Hipparchus library. The changes are mainly adaptations of the signatures to space dynamics.
- the type of dependent variable t has been changed from
double
toAbsoluteDate
- the type of state vector y has been changed from
double[]
toSpacecraftState
- Author:
- Luc Maisonobe, Pascal Parraud
-
Interface Summary Interface Description AdaptableInterval This interface represents an event checking interval that depends on state.EnablingPredicate This interface represents an event enabling predicate function.EventDetector This interface represents space-dynamics aware events detectors.EventDetectorsProvider Interface for building event detectors for force models and maneuver parameters.FieldAdaptableInterval<T extends CalculusFieldElement<T>> This interface represents an event checking interval that depends on state.FieldEnablingPredicate<T extends CalculusFieldElement<T>> This interface represents an event enabling predicate function.FieldEventDetector<T extends CalculusFieldElement<T>> This interface represents space-dynamics aware events detectors. -
Class Summary Class Description AbstractDetector<T extends AbstractDetector<T>> Common parts shared by several orbital events finders.AdapterDetector Base class for adapting an existing detector.AlignmentDetector Finder for satellite/body alignment events in orbital plane.AltitudeDetector Finder for satellite altitude crossing events.AngularSeparationDetector Detects when spacecraft comes close to a moving beacon, as seen from a moving observer.AngularSeparationFromSatelliteDetector Detects when two moving objects come close to each other, as seen from spacecraft.ApsideDetector Finder for apside crossing events.BetaAngleDetector Finder for beta angle crossing events.BooleanDetector This class provides AND and OR operations for event detectors.CylindricalShadowEclipseDetector Event detector for eclipses from a single, infinitely-distant light source, occulted by a spherical central body.DateDetector Finder for date events.EclipseDetector Finder for satellite eclipse related events.ElevationDetector Finder for satellite raising/setting events that allows for the setting of azimuth and/or elevation bounds or a ground azimuth/elevation mask input.ElevationExtremumDetector Detector for elevation extremum with respect to a ground point.EventEnablingPredicateFilter Wrapper used to detect events only when enabled by an external predicated function.EventShifter Wrapper shifting events occurrences times.EventsLogger This class logs events detectors events during propagation.EventsLogger.LoggedEvent Class for logged events entries.EventSlopeFilter<T extends EventDetector> Wrapper used to detect only increasing or decreasing events.EventState<T extends EventDetector> This class handles the state for oneevent detector
during integration steps.EventState.EventOccurrence Class to hold the data related to an event occurrence that is needed to decide how to modify integration.ExtremumApproachDetector Finder for extremum approach events.FieldAbstractDetector<D extends FieldAbstractDetector<D,T>,T extends CalculusFieldElement<T>> Common parts shared by several orbital events finders.FieldAdapterDetector<T extends CalculusFieldElement<T>> Base class for adapting an existing detector.FieldAltitudeDetector<T extends CalculusFieldElement<T>> Finder for satellite altitude crossing events.FieldApsideDetector<T extends CalculusFieldElement<T>> Finder for apside crossing events.FieldBetaAngleDetector<T extends CalculusFieldElement<T>> Finder for beta angle crossing events.FieldBooleanDetector<T extends CalculusFieldElement<T>> This class provides AND and OR operations for event detectors.FieldCylindricalShadowEclipseDetector<T extends CalculusFieldElement<T>> Event detector for eclipses from a single, infinitely-distant light source, occulted by a spherical central body.FieldDateDetector<T extends CalculusFieldElement<T>> Finder for date events.FieldEclipseDetector<T extends CalculusFieldElement<T>> Finder for satellite eclipse related events.FieldElevationDetector<T extends CalculusFieldElement<T>> Finder for satellite raising/setting events that allows for the setting of azimuth and/or elevation bounds or a ground azimuth/elevation mask input.FieldElevationExtremumDetector<T extends CalculusFieldElement<T>> Detector for elevation extremum with respect to a ground point.FieldEventEnablingPredicateFilter<T extends CalculusFieldElement<T>> Wrapper used to detect events only when enabled by an external predicated function.FieldEventsLogger<T extends CalculusFieldElement<T>> This class logs events detectors events during propagation.FieldEventsLogger.FieldLoggedEvent<T extends CalculusFieldElement<T>> Class for logged events entries.FieldEventSlopeFilter<D extends FieldEventDetector<T>,T extends CalculusFieldElement<T>> Wrapper used to detect only increasing or decreasing events.FieldEventState<D extends FieldEventDetector<T>,T extends CalculusFieldElement<T>> This class handles the state for oneevent detector
during integration steps.FieldEventState.EventOccurrence<T extends CalculusFieldElement<T>> Class to hold the data related to an event occurrence that is needed to decide how to modify integration.FieldExtremumApproachDetector<T extends CalculusFieldElement<T>> Finder for extremum approach events.FieldFunctionalDetector<T extends CalculusFieldElement<T>> A detector that implements theFieldFunctionalDetector.g(FieldSpacecraftState)
function using a lambda that can be set usingFieldFunctionalDetector.withFunction(Function)
.FieldLatitudeCrossingDetector<T extends CalculusFieldElement<T>> Detector for geographic latitude crossing.FieldLatitudeRangeCrossingDetector<T extends CalculusFieldElement<T>> Detector for geographic latitude crossing.FieldLongitudeCrossingDetector<T extends CalculusFieldElement<T>> Detector for geographic longitude crossing.FieldLongitudeRangeCrossingDetector<T extends CalculusFieldElement<T>> Detector for geographic longitude crossing.FieldNegateDetector<T extends CalculusFieldElement<T>> An event detector that negates the sign on another event detector'sg
function.FieldNodeDetector<T extends CalculusFieldElement<T>> Finder for node crossing events.FieldOfViewDetector Finder for target entry/exit events with respect to a satellite sensorField Of View
.FieldParameterDrivenDateIntervalDetector<T extends CalculusFieldElement<T>> Detector for date intervals that may be offset thanks to parameter drivers.FieldRelativeDistanceDetector<T extends CalculusFieldElement<T>> Detector of specific value for the distance relative to another trajectory (using the Euclidean norm).FootprintOverlapDetector Detector triggered by geographical region entering/leaving a spacecraft sensorField Of View
.FunctionalDetector A detector that implements theFunctionalDetector.g(SpacecraftState)
function using a lambda that can be set usingFunctionalDetector.withFunction(ToDoubleFunction)
.GeographicZoneDetector Detector for entry/exit of a zone defined by geographic boundaries.GroundAtNightDetector Detector for ground location being at night.GroundFieldOfViewDetector Finder for satellite entry/exit events with respect to a sensorField Of View
attached to an arbitrary frame.HaloXZPlaneCrossingDetector Detector for XZ Plane crossing.InterSatDirectViewDetector Detector for inter-satellites direct view (i.e.LatitudeCrossingDetector Detector for geographic latitude crossing.LatitudeExtremumDetector Detector for geographic latitude extremum.LatitudeRangeCrossingDetector Detector for geographic latitude crossing.LongitudeCrossingDetector Detector for geographic longitude crossing.LongitudeExtremumDetector Detector for geographic longitude extremum.LongitudeRangeCrossingDetector Detector for geographic longitude crossing.MagneticFieldDetector Detector for Earth magnetic field strength.NegateDetector An event detector that negates the sign on another event detector'sg
function.NodeDetector Finder for node crossing events.ParameterDrivenDateIntervalDetector Detector for date intervals that may be offset thanks to parameter drivers.PositionAngleDetector Detector for in-orbit position angle.RelativeDistanceDetector Detector of specific value for the distance relative to another trajectory (using the Euclidean norm). -
Enum Summary Enum Description FilterType Enumerate forfiltering events
.VisibilityTrigger Enumerate for triggering visibility of spherical bodies.