org.orekit.propagation.events

Class ElevationDetector

java.lang.Object

org.orekit.propagation.events.AbstractDetector<ElevationDetector>

org.orekit.propagation.events.ElevationDetector

All Implemented Interfaces:

EventDetector

public class ElevationDetector
extends AbstractDetector<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. Each calculation be configured to use atmospheric refraction as well.

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

Since:

6.1

Author:

Hank Grabowski

Field Summary

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

DEFAULT_MAX_ITER, DEFAULT_MAXCHECK, DEFAULT_THRESHOLD

Constructor Summary

Constructors

Constructor and Description
ElevationDetector(double maxCheck, double threshold, TopocentricFrame topo) Creates an instance of Elevation detector based on passed in topocentric frame and overrides of default maximal checking interval and convergence threshold values.
ElevationDetector(TopocentricFrame topo) Creates an instance of Elevation detector based on passed in topocentric frame and the minimum elevation angle.

Method Summary

Modifier and Type	Method and Description
protected ElevationDetector	create(double newMaxCheck, double newThreshold, int newMaxIter, EventHandler<? super ElevationDetector> newHandler) Build a new instance.
double	g(SpacecraftState s) Compute the value of the switching function.
ElevationMask	getElevationMask() Returns the currently configured elevation mask.
double	getMinElevation() Returns the currently configured minimum valid elevation value.
AtmosphericRefractionModel	getRefractionModel() Returns the currently configured refraction model.
TopocentricFrame	getTopocentricFrame() Returns the currently configured topocentric frame definitions.
ElevationDetector	withConstantElevation(double newMinElevation) Setup the minimum elevation for detection.
ElevationDetector	withElevationMask(ElevationMask newElevationMask) Setup the elevation mask for detection using the passed in mask object.
ElevationDetector	withRefraction(AtmosphericRefractionModel newRefractionModel) Setup the elevation detector to use an atmospheric refraction model in its calculations.

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

eventOccurred, getHandler, getMaxCheckInterval, getMaxIterationCount, getThreshold, init, isForward, resetState, withHandler, withMaxCheck, withMaxIter, withThreshold

Methods inherited from class java.lang.Object

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

Constructor Detail

ElevationDetector

public ElevationDetector(TopocentricFrame topo)

Creates an instance of Elevation detector based on passed in topocentric frame and the minimum elevation angle.

uses default values for maximal checking interval (AbstractDetector.DEFAULT_MAXCHECK) and convergence threshold (AbstractDetector.DEFAULT_THRESHOLD).

Parameters:

topo - reference to a topocentric model

See Also:

withConstantElevation(double), withElevationMask(ElevationMask), withRefraction(AtmosphericRefractionModel)

ElevationDetector

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

Creates an instance of Elevation detector based on passed in topocentric frame and overrides of default maximal checking interval and convergence threshold values.

Parameters:

maxCheck - maximum checking interval (s)

threshold - maximum divergence threshold (s)

topo - reference to a topocentric model

See Also:

withConstantElevation(double), withElevationMask(ElevationMask), withRefraction(AtmosphericRefractionModel)

Method Detail

create

protected ElevationDetector create(double newMaxCheck,
                                   double newThreshold,
                                   int newMaxIter,
                                   EventHandler<? super ElevationDetector> newHandler)

Build a new instance.

Specified by:

create in class AbstractDetector<ElevationDetector>

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

getElevationMask

public ElevationMask getElevationMask()

Returns the currently configured elevation mask.

Returns:

elevation mask (null if instance has been configured with withConstantElevation(double)

See Also:

withElevationMask(ElevationMask)

getMinElevation

public double getMinElevation()

Returns the currently configured minimum valid elevation value.

Returns:

minimum elevation value (Double.NaN if instance has been configured with withElevationMask(ElevationMask)

See Also:

withConstantElevation(double)

getRefractionModel

public AtmosphericRefractionModel getRefractionModel()

Returns the currently configured refraction model.

Returns:

refraction model

See Also:

withRefraction(AtmosphericRefractionModel)

getTopocentricFrame

public TopocentricFrame getTopocentricFrame()

Returns the currently configured topocentric frame definitions.

Returns:

topocentric frame definition

g

public double g(SpacecraftState s)

Compute the value of the switching function. This function measures the difference between the current elevation (and azimuth if necessary) and the reference mask or minimum value.

Specified by:

g in interface EventDetector

Specified by:

g in class AbstractDetector<ElevationDetector>

Parameters:

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

Returns:

value of the switching function

withConstantElevation

public ElevationDetector withConstantElevation(double newMinElevation)

Setup the minimum elevation for detection.

This will override an elevation mask if it has been configured as such previously.

Parameters:

newMinElevation - minimum elevation for visibility in radians (rad)

Returns:

a new detector with updated configuration (the instance is not changed)

Since:

6.1

See Also:

getMinElevation()

withElevationMask

public ElevationDetector withElevationMask(ElevationMask newElevationMask)

Setup the elevation mask for detection using the passed in mask object.

Parameters:

newElevationMask - elevation mask to use for the computation

Returns:

a new detector with updated configuration (the instance is not changed)

Since:

6.1

See Also:

getElevationMask()

withRefraction

public ElevationDetector withRefraction(AtmosphericRefractionModel newRefractionModel)

Setup the elevation detector to use an atmospheric refraction model in its calculations.

To disable the refraction when copying an existing elevation detector, call this method with a null argument.

Parameters:

newRefractionModel - refraction model to use for the computation

Returns:

a new detector with updated configuration (the instance is not changed)

Since:

6.1

See Also:

getRefractionModel()