org.orekit.propagation.events

Class DateDetector

java.lang.Object

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

org.orekit.propagation.events.DateDetector

All Implemented Interfaces:

EventDetector, TimeStamped

public class DateDetector
extends AbstractDetector<DateDetector>
implements TimeStamped

Finder for date events.

This class finds date events (i.e. occurrence of some predefined dates).

As of version 5.1, it is an enhanced date detector:

• it can be defined without prior date (DateDetector(double, double, TimeStamped...))
• several dates can be added (addEventDate(AbsoluteDate))

The gap between the added dates must be more than the maxCheck.

The default implementation behavior is to stop propagation at the first event date occurrence. This can be changed by calling AbstractDetector.withHandler(EventHandler) after construction.

Author:

Luc Maisonobe, Pascal Parraud

See Also:

Propagator.addEventDetector(EventDetector)

Field Summary

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

DEFAULT_MAX_ITER, DEFAULT_MAXCHECK, DEFAULT_THRESHOLD

Constructor Summary

Constructors

Constructor and Description
DateDetector(AbsoluteDate target) Build a new instance.
DateDetector(double maxCheck, double threshold, TimeStamped... dates) Build a new instance.

Method Summary

Modifier and Type	Method and Description
void	addEventDate(AbsoluteDate target) Add an event date.
protected DateDetector	create(double newMaxCheck, double newThreshold, int newMaxIter, EventHandler<? super DateDetector> newHandler) Build a new instance.
double	g(SpacecraftState s) Compute the value of the switching function.
AbsoluteDate	getDate() Get the current event date according to the propagator.

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

DateDetector

public DateDetector(double maxCheck,
                    double threshold,
                    TimeStamped... dates)

Build a new instance.

First event dates are set here, but others can be added later with addEventDate(AbsoluteDate).

Parameters:

maxCheck - maximum checking interval (s)

threshold - convergence threshold (s)

dates - list of event dates

See Also:

addEventDate(AbsoluteDate)

DateDetector

public DateDetector(AbsoluteDate target)

Build a new instance.

This constructor is dedicated to single date detection. max check interval is set to 1.0e10, so almost no other date can be added. Tolerance is set to 1.0e-9.

Parameters:

target - target date

See Also:

addEventDate(AbsoluteDate)

Method Detail

create

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

Build a new instance.

Specified by:

create in class AbstractDetector<DateDetector>

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

g

public double g(SpacecraftState s)

Compute the value of the switching function. This function measures the difference between the current and the target date.

Specified by:

g in interface EventDetector

Specified by:

g in class AbstractDetector<DateDetector>

Parameters:

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

Returns:

value of the switching function

getDate

public AbsoluteDate getDate()

Get the current event date according to the propagator.

Specified by:

getDate in interface TimeStamped

Returns:

event date

addEventDate

public void addEventDate(AbsoluteDate target)
                  throws IllegalArgumentException

Add an event date.

The date to add must be:

• less than the smallest already registered event date minus the maxCheck
• or more than the largest already registered event date plus the maxCheck

Parameters:

target - target date

Throws:

IllegalArgumentException - if the date is too close from already defined interval

See Also:

DateDetector(double, double, TimeStamped...)