org.orekit.propagation.events
Class ElevationDetector

java.lang.Object
  org.orekit.propagation.events.AbstractDetector
      org.orekit.propagation.events.ElevationDetector

All Implemented Interfaces:

Serializable, EventDetector

public class ElevationDetector
extends AbstractDetector

Finder for satellite raising/setting events.

This class finds elevation events (i.e. satellite raising and setting).

The default implementation behavior is to continue propagation at raising and to stop propagation at setting. This can be changed by using provided constructors.

Author:

Luc Maisonobe

See Also:

Propagator.addEventDetector(EventDetector), Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.orekit.propagation.events.EventDetector

EventDetector.Action

Field Summary

Fields inherited from class org.orekit.propagation.events.AbstractDetector

DEFAULT_MAXCHECK, DEFAULT_THRESHOLD

Fields inherited from interface org.orekit.propagation.events.EventDetector

DECREASING, INCREASING, INCREASING_DECREASING

Constructor Summary

ElevationDetector(double elevation, TopocentricFrame topo)
Build a new elevation detector.

ElevationDetector(double elevation, TopocentricFrame topo, double maxCheck)
Build a new elevation detector.

ElevationDetector(double elevation, TopocentricFrame topo, double maxCheck, double threshold)
Build a new elevation detector.

ElevationDetector(double elevation, TopocentricFrame topo, double maxCheck, double threshold, EventDetector.Action raising, EventDetector.Action setting)
Build a new elevation detector.

ElevationDetector(double elevation, TopocentricFrame topo, double maxCheck, double threshold, EventDetector.Action raising, EventDetector.Action setting, boolean removeRaising, boolean removeSetting)
Build a new elevation detector.

Method Summary

EventDetector.Action	eventOccurred(SpacecraftState s, boolean increasing, boolean forward) Handle an elevation event and choose what to do next.
double	g(SpacecraftState s) Compute the value of the switching function.
double	getElevation() Get the threshold elevation value.
TopocentricFrame	getTopocentricFrame() Get the topocentric frame.
boolean	shouldBeRemoved() This method is called after EventDetector.eventOccurred(org.orekit.propagation.SpacecraftState, boolean, boolean) has been triggered.

Methods inherited from class org.orekit.propagation.events.AbstractDetector

getMaxCheckInterval, getMaxIterationCount, getSlopeSelection, getThreshold, init, resetState

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ElevationDetector

public ElevationDetector(double elevation,
                         TopocentricFrame topo)

Build a new elevation detector.

This simple constructor takes default values for maximal checking interval (AbstractDetector.DEFAULT_MAXCHECK) and convergence threshold (AbstractDetector.DEFAULT_THRESHOLD).

Parameters:

elevation - threshold elevation value (rad)

topo - topocentric frame in which elevation should be evaluated

ElevationDetector

public ElevationDetector(double elevation,
                         TopocentricFrame topo,
                         double maxCheck)

Build a new elevation detector.

This constructor takes default value for convergence threshold (AbstractDetector.DEFAULT_THRESHOLD).

The maximal interval between elevation checks should be smaller than the half duration of the minimal pass to handle, otherwise some short passes could be missed.

Parameters:

elevation - threshold elevation value (rad)

topo - topocentric frame in which elevation should be evaluated

maxCheck - maximal checking interval (s)

ElevationDetector

public ElevationDetector(double elevation,
                         TopocentricFrame topo,
                         double maxCheck,
                         double threshold)

Build a new elevation detector.

The maximal interval between elevation checks should be smaller than the half duration of the minimal pass to handle, otherwise some short passes could be missed.

The default implementation behavior is to continue propagation at raising and to stop propagation at setting.

Parameters:

elevation - threshold elevation value (rad)

topo - topocentric frame in which elevation should be evaluated

maxCheck - maximal checking interval (s)

threshold - convergence threshold (s)

ElevationDetector

public ElevationDetector(double elevation,
                         TopocentricFrame topo,
                         double maxCheck,
                         double threshold,
                         EventDetector.Action raising,
                         EventDetector.Action setting)

Build a new elevation detector.

The maximal interval between elevation checks should be smaller than the half duration of the minimal pass to handle, otherwise some short passes could be missed.

Parameters:

elevation - threshold elevation value (rad)

topo - topocentric frame in which elevation should be evaluated

maxCheck - maximal checking interval (s)

threshold - convergence threshold (s)

raising - action performed when propagation at raising

setting - action performed when propagation at setting

ElevationDetector

public ElevationDetector(double elevation,
                         TopocentricFrame topo,
                         double maxCheck,
                         double threshold,
                         EventDetector.Action raising,
                         EventDetector.Action setting,
                         boolean removeRaising,
                         boolean removeSetting)

Build a new elevation detector.

The maximal interval between elevation checks should be smaller than the half duration of the minimal pass to handle, otherwise some short passes could be missed.

Parameters:

elevation - threshold elevation value (rad)

topo - topocentric frame in which elevation should be evaluated

maxCheck - maximal checking interval (s)

threshold - convergence threshold (s)

raising - action performed when propagation at raising

setting - action performed when propagation at setting

removeRaising - if detector should be removed at raising

removeSetting - if detector should be removed at setting

Since:

3.1

Method Detail

getElevation

public double getElevation()

Get the threshold elevation value.

Returns:

the threshold elevation value (rad)

getTopocentricFrame

public TopocentricFrame getTopocentricFrame()

Get the topocentric frame.

Returns:

the topocentric frame

eventOccurred

public EventDetector.Action eventOccurred(SpacecraftState s,
                                          boolean increasing,
                                          boolean forward)
                                   throws OrekitException

Handle an elevation event and choose what to do next.

Specified by:

eventOccurred in interface EventDetector

Specified by:

eventOccurred in class AbstractDetector

Parameters:

s - the current state information : date, kinematics, attitude

increasing - if true, the value of the switching function increases when times increases around event

forward - if true, the integration variable (time) increases during integration.

Returns:

the action performed when propagation raising or setting.

Throws:

OrekitException - if some specific error occurs

shouldBeRemoved

public boolean shouldBeRemoved()

This method is called after EventDetector.eventOccurred(org.orekit.propagation.SpacecraftState, boolean, boolean) has been triggered. It returns true if the current detector should be removed after first event detection. WARNING: this method can be called only once a event has been triggered. Before, the value is not available.

Specified by:

shouldBeRemoved in interface EventDetector

Specified by:

shouldBeRemoved in class AbstractDetector

Returns:

true if the current detector should be removed after first event detection

g

public double g(SpacecraftState s)
         throws OrekitException

Compute the value of the switching function. This function measures the difference between the current elevation and the threshold elevation.

Specified by:

g in interface EventDetector

Specified by:

g in class AbstractDetector

Parameters:

s - the current state information: date, kinematics, attitude

Returns:

value of the switching function

Throws:

OrekitException - if some specific error occurs