fr.cnes.sirius.patrius.stela.propagation

Class StelaGTOPropagator

java.lang.Object

fr.cnes.sirius.patrius.stela.propagation.StelaAbstractPropagator

fr.cnes.sirius.patrius.stela.propagation.StelaGTOPropagator

All Implemented Interfaces:

PVCoordinatesProvider, Propagator, SpacecraftStateProvider, Serializable

public class StelaGTOPropagator
extends StelaAbstractPropagator

STELA propagator for Geostationnary Transfert Orbits (GTO).

Since:

1.3

Version:

$Id$

Author:

Tiziana Sabatini, Cedric Dental

See Also:

Serialized Form

Concurrency :

not thread-safe

Concurrency comment :

use of mutable attributes

Field Summary

Fields

Modifier and Type	Field and Description
protected AbsoluteDate	maxDate Max date after which simulation has to fail if exception mechanism was triggered
protected int	stepCounter Step counter for drag computation.
protected boolean	wasException Was the exception mechanism triggered already

Fields inherited from class fr.cnes.sirius.patrius.stela.propagation.StelaAbstractPropagator

attitudeProviderByDefault, attitudeProviderEvents, attitudeProviderForces, eventsStates, integrator, oldStepHandler

Fields inherited from interface fr.cnes.sirius.patrius.propagation.Propagator

EPHEMERIS_GENERATION_MODE, MASTER_MODE, SLAVE_MODE

Constructor Summary

Constructors

Constructor and Description
StelaGTOPropagator(FirstOrderIntegrator integr) Build a StelaGTOPropagator.
StelaGTOPropagator(FirstOrderIntegrator integr, AttitudeProvider inAttitudeProviderForces, AttitudeProvider inAttitudeProviderEvents, StelaBasicInterpolator inInter, double maxShiftIn, double minStepSizeIn) Build a StelaGTOPropagator.
StelaGTOPropagator(FirstOrderIntegrator integr, AttitudeProvider inAttitudeProvider, StelaBasicInterpolator inInter, double maxShiftIn, double minStepSizeIn) Build a StelaGTOPropagator.
StelaGTOPropagator(FirstOrderIntegrator integr, double maxShiftIn, double minStepSizeIn) Build a StelaGTOPropagator.

Method Summary

Modifier and Type	Method and Description
void	addAdditionalEquations(StelaAdditionalEquations addEquations) Add a set of user-specified additional equations to be integrated along with the orbit propagation.
void	addAttitudeEquation(StelaAttitudeAdditionalEquations addEqu) Add a set of user-specified attitude equations to be integrated along with the orbit propagation.
void	addForceModel(StelaForceModel forceModel) Add a force model to the global perturbation model.
protected void	dragComputation() update drag computation need before creating differential equations
List<StelaAdditionalEquations>	getAddEquations() Get the additional equations.
protected double[]	getdDragdt() Method that returns the drag value in memory, only used for n steps drag computation purposes
List<StelaForceModel>	getForceModels() Get perturbing force models list.
ForcesStepHandler	getForcesStepHandler() Getter for forces step handler.
List<AbstractStelaGaussContribution>	getGaussForceModels() Get perturbing Gauss force models list.
List<AbstractStelaLagrangeContribution>	getLagrangeForceModels() Get perturbing Lagrange force models list.
protected double	getMass(AbsoluteDate date) Get the mass.
OrbitNatureConverter	getOrbitNatureConverter() Get the mean/osculating orbit converter.
AbsoluteDate	getReferenceDate() Get the reference date
protected List<PatriusStepHandler>	getStepHandlers() Provides a list of step handlers to be performed during propagation.
protected void	initialOrbitTest(SpacecraftState initialState2) tests whether the initial orbit is under Perigee Altitude
protected boolean	isRecomputeDrag()
SpacecraftState	propagate(AbsoluteDate start, AbsoluteDate target) Propagate from a start date towards a target date.
protected SpacecraftState	propagateSpacecraftState(AbsoluteDate date) Extrapolate a spacecraftState up to a specific target date.
protected SpacecraftState	propagationManagement(SpacecraftState state, double stepSize, double dt, AbsoluteDate target) Manages the current step, method to override when user wants to deal with exceptions during the propagation.
protected SpacecraftState	propagationManagementLoop(double currentStepSize, AbsoluteDate target, double dt, String message) Reduce step size until propagation over next step returns physical values.
void	removeForceModels() Remove all perturbing force models from the global perturbation model.
void	setAttitudeProvider(AttitudeProvider attitudeProvider) Set attitude provider for forces and events computation.
void	setAttitudeProviderEvents(AttitudeProvider attitudeEventsProvider) Set attitude provider for events computation.
void	setAttitudeProviderForces(AttitudeProvider attitudeForcesProvider) Set attitude provider for forces computation.
protected void	setdDragdt(double[] indDragdt) Specify the drag values, only used for n steps drag computation purposes
void	setInitialState(SpacecraftState initialState, double massIn, boolean isOsculatingIn) Set the initial state.
void	setNatureConverter(List<StelaForceModel> forceModels) Set the force models to be used in the mean <=> osculating converter.

Methods inherited from class fr.cnes.sirius.patrius.stela.propagation.StelaAbstractPropagator

acceptStep, addAdditionalStateProvider, addEventDetector, addTimeDerivativeData, basicPropagate, clearEventsDetectors, getAttitudeProvider, getAttitudeProviderEvents, getAttitudeProviderForces, getEventsDetectors, getFrame, getGeneratedEphemeris, getInitialState, getMode, getPVCoordinates, getPvProvider, getSpacecraftState, getTimeDerivativesList, goAhead, isRegisterTimeDerivatives, isStoreTimeDerivatives, propagate, resetInitialState, setEphemerisMode, setIntegrator, setMasterMode, setMasterMode, setOrbitFrame, setSlaveMode, setStartDate, setStoreTimeDerivatives

Methods inherited from class java.lang.Object

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

Methods inherited from interface fr.cnes.sirius.patrius.propagation.Propagator

getNativeFrame

Field Detail

wasException

protected boolean wasException

Was the exception mechanism triggered already

maxDate

protected AbsoluteDate maxDate

Max date after which simulation has to fail if exception mechanism was triggered

stepCounter

protected int stepCounter

Step counter for drag computation.

Constructor Detail

StelaGTOPropagator

public StelaGTOPropagator(FirstOrderIntegrator integr)
                   throws PatriusException

Build a StelaGTOPropagator.

After creation, there is no orbit, method setInitialState must be called. This constructor uses a Default Law as AttitudeProvider. For a specific Attitude Provider please use the other constructor. After creation, there are no perturbing forces at all. This means that if addForceModel is not called after creation, the integrated orbit will follow a simple Keplerian evolution.

During reentry, no correction is performed if some results are not physical. As a result, an exception will be thrown if obtained results are not physical.

Parameters:

integr - the first order integrator to use for extrapolation

Throws:

PatriusException - exception in reset initial state

StelaGTOPropagator

public StelaGTOPropagator(FirstOrderIntegrator integr,
                          double maxShiftIn,
                          double minStepSizeIn)
                   throws PatriusException

Build a StelaGTOPropagator.

After creation, there is no orbit, method setInitialState must be called. This constructor uses a the AttitudeProvider given by the user. After creation, there are no perturbing forces at all. This means that if addForceModel is not called after creation, the integrated orbit will follow a simple Keplerian evolution.

No attitude provider is defined. The user should call setAttitudeProvider(AttitudeProvider) or setAttitudeProviderEvents(AttitudeProvider) or setAttitudeProviderForces(AttitudeProvider)

Parameters:

integr - the first order integrator to use for extrapolation

maxShiftIn - Maximum number of integration steps STELA will try to correct to get some physical results (mostly during reentry since integration step is too large). If 0, not correction is performed. If more corrections are required, an exception will be thrown

minStepSizeIn - Smallest integration stepsize allowed. STELA will try to reduce stepsize during reentry to try to get some physical results. If equals to integrator step size, not correction is done. If a smaller stepsize than provided value is required, an exception will be thrown

Throws:

PatriusException - exception in reset initial state

StelaGTOPropagator

public StelaGTOPropagator(FirstOrderIntegrator integr,
                          AttitudeProvider inAttitudeProvider,
                          StelaBasicInterpolator inInter,
                          double maxShiftIn,
                          double minStepSizeIn)
                   throws PatriusException

Build a StelaGTOPropagator.

After creation, there is no orbit, method setInitialState must be called. This constructor uses a single AttitudeProvider given by the user. After creation, there are no perturbing forces at all. This means that if addForceModel is not called after creation, the integrated orbit will follow a simple Keplerian evolution.

Parameters:

integr - the first order integrator to use for extrapolation

inAttitudeProvider - attitude provider

inInter - the interpolator

maxShiftIn - Maximum number of integration steps STELA will try to correct to get some physical results (mostly during reentry since integration step is too large). If 0, not correction is performed. If more corrections are required, an exception will be thrown

minStepSizeIn - Smallest integration stepsize allowed. STELA will try to reduce stepsize during reentry to try to get some physical results. If equals to integrator step size, not correction is done. If a smaller stepsize than provided value is required, an exception will be thrown

Throws:

PatriusException - exception in reset initial state

StelaGTOPropagator

public StelaGTOPropagator(FirstOrderIntegrator integr,
                          AttitudeProvider inAttitudeProviderForces,
                          AttitudeProvider inAttitudeProviderEvents,
                          StelaBasicInterpolator inInter,
                          double maxShiftIn,
                          double minStepSizeIn)
                   throws PatriusException

Build a StelaGTOPropagator.

After creation, there is no orbit, method setInitialState must be called. This constructor uses AttitudeProvider for forces and events computations given by the user. After creation, there are no perturbing forces at all. This means that if addForceModel is not called after creation, the integrated orbit will follow a simple Keplerian evolution.

Parameters:

integr - the first order integrator to use for extrapolation

inAttitudeProviderForces - attitude provider for forces computation

inAttitudeProviderEvents - attitude provider for events computation

inInter - the interpolator

maxShiftIn - Maximum number of integration steps STELA will try to correct to get some physical results (mostly during reentry since integration step is too large). If 0, not correction is performed. If more corrections are required, an exception will be thrown

minStepSizeIn - Smallest integration stepsize allowed. STELA will try to reduce stepsize during reentry to try to get some physical results. If equals to integrator step size, not correction is done. If a smaller stepsize than provided value is required, an exception will be thrown

Throws:

PatriusException - exception in reset initial state

Method Detail

isRecomputeDrag

protected boolean isRecomputeDrag()

Returns:

the recomputeDrag

setInitialState

public void setInitialState(SpacecraftState initialState,
                            double massIn,
                            boolean isOsculatingIn)
                     throws PatriusException

Set the initial state.

Parameters:

initialState - initial state (no mass information should be provided)

massIn - the initial mass

isOsculatingIn - true if initial state is osculating

Throws:

PatriusException - OrekitException

See Also:

StelaAbstractPropagator.propagate(AbsoluteDate)

addForceModel

public void addForceModel(StelaForceModel forceModel)

Add a force model to the global perturbation model.

If this method is not called at all, the integrated orbit will follow a simple keplerian evolution.

Parameters:

forceModel - perturbing StelaForceModel to add

See Also:

removeForceModels()

setNatureConverter

public void setNatureConverter(List<StelaForceModel> forceModels)

Set the force models to be used in the mean <=> osculating converter. By default, all force models are included.

Beware to call this method after the addForceModel(StelaForceModel) method since the latter overrides the nature converter.

Parameters:

forceModels - force models to be used in the mean <=> osculating converter

removeForceModels

public void removeForceModels()

Remove all perturbing force models from the global perturbation model.

Once all perturbing forces have been removed (and as long as no new force model is added), the integrated orbit will follow a simple keplerian evolution.

See Also:

addForceModel(StelaForceModel)

getForceModels

public List<StelaForceModel> getForceModels()

Get perturbing force models list.

Returns:

list of all perturbing force models

See Also:

addForceModel(StelaForceModel), removeForceModels()

getGaussForceModels

public List<AbstractStelaGaussContribution> getGaussForceModels()

Get perturbing Gauss force models list.

Returns:

list of Gauss perturbing force models

See Also:

addForceModel(StelaForceModel), removeForceModels()

getLagrangeForceModels

public List<AbstractStelaLagrangeContribution> getLagrangeForceModels()

Get perturbing Lagrange force models list.

Returns:

list of Lagrange perturbing force models

See Also:

addForceModel(StelaForceModel), removeForceModels()

addAdditionalEquations

public void addAdditionalEquations(StelaAdditionalEquations addEquations)

Add a set of user-specified additional equations to be integrated along with the orbit propagation.

Parameters:

addEquations - additional equations

See Also:

NumericalPropagator

addAttitudeEquation

public void addAttitudeEquation(StelaAttitudeAdditionalEquations addEqu)

Add a set of user-specified attitude equations to be integrated along with the orbit propagation. If the set of attitude equations is already registered for the current attitude, it is replaced by the new one.

Parameters:

addEqu - attitude additional equations for Stela GTO propagator

setAttitudeProvider

public void setAttitudeProvider(AttitudeProvider attitudeProvider)

Set attitude provider for forces and events computation. A default attitude provider is available in ConstantAttitudeLaw.

Specified by:

setAttitudeProvider in interface Propagator

Overrides:

setAttitudeProvider in class StelaAbstractPropagator

Parameters:

attitudeProvider - attitude provider

setAttitudeProviderForces

public void setAttitudeProviderForces(AttitudeProvider attitudeForcesProvider)

Set attitude provider for forces computation. A default attitude provider is available in ConstantAttitudeLaw.

Specified by:

setAttitudeProviderForces in interface Propagator

Overrides:

setAttitudeProviderForces in class StelaAbstractPropagator

Parameters:

attitudeForcesProvider - attitude provider for forces computation

setAttitudeProviderEvents

public void setAttitudeProviderEvents(AttitudeProvider attitudeEventsProvider)

Set attitude provider for events computation. A default attitude provider is available in ConstantAttitudeLaw.

Specified by:

setAttitudeProviderEvents in interface Propagator

Overrides:

setAttitudeProviderEvents in class StelaAbstractPropagator

Parameters:

attitudeEventsProvider - attitude provider for events computation

propagate

public SpacecraftState propagate(AbsoluteDate start,
                                 AbsoluteDate target)
                          throws PropagationException

Propagate from a start date towards a target date.

Those propagators use a start date and a target date to compute the propagated state. For propagators using event detection mechanism, if the provided start date is different from the initial state date, a first, simple propagation is performed, without processing any event computation. Then complete propagation is performed from start date to target date.

Note that mean elements are returned.

Specified by:

propagate in interface Propagator

Overrides:

propagate in class StelaAbstractPropagator

Parameters:

start - start date from which orbit state should be propagated

target - target date to which orbit state should be propagated

Returns:

propagated state

Throws:

PropagationException - if state cannot be propagated

getStepHandlers

protected List<PatriusStepHandler> getStepHandlers()

Provides a list of step handlers to be performed during propagation.

Specified by:

getStepHandlers in class StelaAbstractPropagator

Returns:

propagation list of step handlers.

initialOrbitTest

protected void initialOrbitTest(SpacecraftState initialState2)
                         throws PatriusException

tests whether the initial orbit is under Perigee Altitude

Parameters:

initialState2 - the initial state

Throws:

PatriusException - the orekit exception

Since:

1.3

propagateSpacecraftState

protected SpacecraftState propagateSpacecraftState(AbsoluteDate date)
                                            throws PatriusException

Extrapolate a spacecraftState up to a specific target date. Note that mean elements are returned.

Specified by:

propagateSpacecraftState in class StelaAbstractPropagator

Parameters:

date - target date for the orbit

Returns:

extrapolated parameters

Throws:

PatriusException - * if some parameters are out of bounds

dragComputation

protected void dragComputation()

update drag computation need before creating differential equations

Since:

1.3

propagationManagement

protected SpacecraftState propagationManagement(SpacecraftState state,
                                                double stepSize,
                                                double dt,
                                                AbsoluteDate target)
                                         throws PatriusException

Manages the current step, method to override when user wants to deal with exceptions during the propagation.

Overrides:

propagationManagement in class StelaAbstractPropagator

Parameters:

state - the current SpacecraftState

stepSize - the current stepsize

dt - the dt time

target - target date to propagate

Returns:

finalState the final spacecraft state

Throws:

PatriusException - Orekit exception

propagationManagementLoop

protected SpacecraftState propagationManagementLoop(double currentStepSize,
                                                    AbsoluteDate target,
                                                    double dt,
                                                    String message)
                                             throws PropagationException

Reduce step size until propagation over next step returns physical values.

Parameters:

currentStepSize - the initial stepSize

target - the target date

dt - the dt time

message - the exception message

Returns:

finalstate the final state

Throws:

PropagationException - a propagation exception

Since:

1.3

getMass

protected double getMass(AbsoluteDate date)
                  throws PropagationException

Get the mass.

Specified by:

getMass in class StelaAbstractPropagator

Parameters:

date - target date for the orbit

Returns:

mass mass

Throws:

PropagationException - if some parameters are out of bounds

getReferenceDate

public AbsoluteDate getReferenceDate()

Get the reference date

Returns:

the reference date.

getAddEquations

public List<StelaAdditionalEquations> getAddEquations()

Get the additional equations.

Returns:

the additional equations.

getOrbitNatureConverter

public OrbitNatureConverter getOrbitNatureConverter()

Get the mean/osculating orbit converter.

Returns:

the mean/osculating orbit converter.

setdDragdt

protected void setdDragdt(double[] indDragdt)

Specify the drag values, only used for n steps drag computation purposes

Parameters:

indDragdt - the drag values to set

getdDragdt

protected double[] getdDragdt()

Method that returns the drag value in memory, only used for n steps drag computation purposes

Returns:

the dDragdt

getForcesStepHandler

public ForcesStepHandler getForcesStepHandler()

Getter for forces step handler.

Returns:

forces step handler