fr.cnes.sirius.patrius.attitudes

Class AbstractAttitudeEphemerisGenerator

java.lang.Object

fr.cnes.sirius.patrius.attitudes.AbstractAttitudeEphemerisGenerator

Direct Known Subclasses:

FixedStepAttitudeEphemerisGenerator, VariableStepAttitudeEphemerisGenerator

public abstract class AbstractAttitudeEphemerisGenerator
extends Object

This abstract class handles the generation of attitude ephemeris from an attitude laws sequence StrictAttitudeLegsSequence.
The ephemeris generation can be done using a fixed time step or a variable time step, setting the generation time interval (the default value is the time interval of the sequence), and the treatment to apply to the transition points of the sequence (ignore them, compute the attitude of the initial date of the laws, compute the attitude of the initial and final date of the laws).

Since:

1.3

Version:

$Id: AbstractAttitudeEphemerisGenerator.java 17582 2017-05-10 12:58:16Z bignon $

Author:

Tiziana Sabatini

See Also:

FixedStepAttitudeEphemerisGenerator, VariableStepAttitudeEphemerisGenerator

Field Summary

Fields

Modifier and Type	Field and Description
static int	NO_TRANSITIONS The transition points are ignored.
protected PVCoordinatesProvider	provider PV coordinate provider.
protected StrictAttitudeLegsSequence<AttitudeLeg>	sequence Attitude legs sequence.
static int	START_END_TRANSITIONS The start and the end point of the laws are computed.
static int	START_TRANSITIONS The start date of the laws are computed.
protected int	transitions Flag specifying what to do with the attitude laws transition points.

Constructor Summary

Constructors

Constructor and Description
AbstractAttitudeEphemerisGenerator(StrictAttitudeLegsSequence<AttitudeLeg> legsSequence, int transitionPoints, PVCoordinatesProvider providerIn) Simple constructor.

Method Summary

Modifier and Type	Method and Description
protected abstract boolean	addLastPoint(AbsoluteDateInterval ephemerisInterval) Decide if adding the last point of the time interval to the ephemeris list.
protected abstract double	computeStep(AbsoluteDate date, AbsoluteDateInterval ephemerisInterval) Computes the step used during attitude ephemeris generation.
SortedSet<Attitude>	generateEphemeris(AbsoluteDateInterval ephemerisInterval, Frame frame) Computes attitude ephemeris using a fixed or variable time step and choosing the interval of validity.
SortedSet<Attitude>	generateEphemeris(Frame frame) Computes attitude ephemeris using a fixed or variable time step.
Attitude	getPreviousAttitude(PVCoordinatesProvider pvProv, AbsoluteDate date, Frame frame) Returns attitude from previous leg (compared to leg matching provided date) from the sequence.
protected AbsoluteDateInterval	getTimeInterval() Returns the underlying sequence time interval.

Methods inherited from class java.lang.Object

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

Field Detail

START_TRANSITIONS

public static final int START_TRANSITIONS

The start date of the laws are computed.

See Also:

Constant Field Values

START_END_TRANSITIONS

public static final int START_END_TRANSITIONS

The start and the end point of the laws are computed.

See Also:

Constant Field Values

NO_TRANSITIONS

public static final int NO_TRANSITIONS

The transition points are ignored.

See Also:

Constant Field Values

sequence

protected final StrictAttitudeLegsSequence<AttitudeLeg> sequence

Attitude legs sequence.

transitions

protected final int transitions

Flag specifying what to do with the attitude laws transition points.

provider

protected final PVCoordinatesProvider provider

PV coordinate provider.

Constructor Detail

AbstractAttitudeEphemerisGenerator

public AbstractAttitudeEphemerisGenerator(StrictAttitudeLegsSequence<AttitudeLeg> legsSequence,
                                          int transitionPoints,
                                          PVCoordinatesProvider providerIn)

Simple constructor.

Parameters:

legsSequence - the sequence of attitude legs.

transitionPoints - what to do with the attitude laws transition points.

providerIn - PV coordinates provider

Method Detail

generateEphemeris

public SortedSet<Attitude> generateEphemeris(Frame frame)
                                      throws PatriusException

Computes attitude ephemeris using a fixed or variable time step. The interval of validity coincides with the time interval of the sequence.

Parameters:

frame - the frame of the computed attitude ephemeris

Returns:

the attitude ephemeris

Throws:

PatriusException - an orekit exception

generateEphemeris

public SortedSet<Attitude> generateEphemeris(AbsoluteDateInterval ephemerisInterval,
                                             Frame frame)
                                      throws PatriusException

Computes attitude ephemeris using a fixed or variable time step and choosing the interval of validity.

Parameters:

ephemerisInterval - the interval of validity of the ephemeris

frame - the frame of the computed attitude ephemeris

Returns:

the attitude ephemeris

Throws:

PatriusException - an orekit exception

getPreviousAttitude

public Attitude getPreviousAttitude(PVCoordinatesProvider pvProv,
                                    AbsoluteDate date,
                                    Frame frame)
                             throws PatriusException

Returns attitude from previous leg (compared to leg matching provided date) from the sequence.

Warning: previous attitude leg has to be defined at provided date. Otherwise null is returned

This method is mainly used for switching sequence in order to retrieve attitude before/after a switch. Thus provided date should be a switching date.

Parameters:

pvProv - spacecraft's position and velocity coordinates provider

date - the date for which the attitude is computed

frame - the frame for which the attitude is computed

Returns:

the attitude if existent, null otherwise

Throws:

PatriusException - thrown if attitude could not be retrieved

computeStep

protected abstract double computeStep(AbsoluteDate date,
                                      AbsoluteDateInterval ephemerisInterval)
                               throws PatriusException

Computes the step used during attitude ephemeris generation.

Parameters:

date - the date

ephemerisInterval - the interval of validity of the ephemeris

Returns:

the computed step

Throws:

PatriusException - an orekit exception

addLastPoint

protected abstract boolean addLastPoint(AbsoluteDateInterval ephemerisInterval)

Decide if adding the last point of the time interval to the ephemeris list.

Parameters:

ephemerisInterval - the interval of validity of the ephemeris.

Returns:

true if the attitude at the last point has to be computed.

getTimeInterval

protected AbsoluteDateInterval getTimeInterval()

Returns the underlying sequence time interval.

Returns:

the underlying sequence time interval