org.orekit.propagation.precomputed
Class Ephemeris

java.lang.Object
  org.orekit.propagation.AbstractPropagator
      org.orekit.propagation.precomputed.Ephemeris

All Implemented Interfaces:

Serializable, BoundedPropagator, Propagator, PVCoordinatesProvider

public class Ephemeris
extends AbstractPropagator
implements BoundedPropagator

This class is designed to accept and handle tabulated orbital entries. Tabulated entries are classified and then extrapolated in way to obtain continuous output, with accuracy and computation methods configured by the user.

Author:

Fabien Maussion, Véronique Pommier-Maurussane, Luc Maisonobe

See Also:

Serialized Form

Field Summary

Fields inherited from class org.orekit.propagation.AbstractPropagator

MASS

Fields inherited from interface org.orekit.propagation.Propagator

EPHEMERIS_GENERATION_MODE, MASTER_MODE, SLAVE_MODE

Constructor Summary

Ephemeris(List<SpacecraftState> states, int interpolationPoints)
Constructor with tabulated states.

Method Summary

SpacecraftState	basicPropagate(AbsoluteDate date) Propagate an orbit without any fancy features.
SpacecraftState	getInitialState() Get the propagator initial state.
AbsoluteDate	getMaxDate() Get the last date of the range.
AbsoluteDate	getMinDate() Get the first date of the range.
PVCoordinates	getPVCoordinates(AbsoluteDate date, Frame frame) Get the PVCoordinates of the body in the selected frame.
protected Orbit	propagateOrbit(AbsoluteDate date) Extrapolate an orbit up to a specific target date.
void	resetInitialState(SpacecraftState state) Try (and fail) to reset the initial state.

Methods inherited from class org.orekit.propagation.AbstractPropagator

acceptStep, addAdditionalStateProvider, addAdditionalStateProvider, addEventDetector, clearEventsDetectors, getAttitudeProvider, getAttitudeProviderEvents, getAttitudeProviderForces, getEventsDetectors, getFrame, getGeneratedEphemeris, getMode, getPvProvider, manageStateFrame, propagate, propagate, setAttitudeProvider, setAttitudeProviderEvents, setAttitudeProviderForces, setEphemerisMode, setMasterMode, setMasterMode, setOrbitFrame, setSlaveMode, setStartDate

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.orekit.propagation.Propagator

addEventDetector, clearEventsDetectors, getAttitudeProvider, getAttitudeProviderEvents, getAttitudeProviderForces, getEventsDetectors, getFrame, getGeneratedEphemeris, getMode, propagate, propagate, setAttitudeProvider, setAttitudeProviderEvents, setAttitudeProviderForces, setEphemerisMode, setMasterMode, setMasterMode, setOrbitFrame, setSlaveMode

Constructor Detail

Ephemeris

public Ephemeris(List<SpacecraftState> states,
                 int interpolationPoints)
          throws MathIllegalArgumentException

Constructor with tabulated states.

Parameters:

states - tabulates states

interpolationPoints - number of points to use in interpolation

Throws:

MathIllegalArgumentException - if the number of states is smaller than the number of points to use in interpolation

Method Detail

getMinDate

public AbsoluteDate getMinDate()

Get the first date of the range.

Specified by:

getMinDate in interface BoundedPropagator

Returns:

the first date of the range

getMaxDate

public AbsoluteDate getMaxDate()

Get the last date of the range.

Specified by:

getMaxDate in interface BoundedPropagator

Returns:

the last date of the range

basicPropagate

public SpacecraftState basicPropagate(AbsoluteDate date)
                               throws PropagationException

Description copied from class: AbstractPropagator

Propagate an orbit without any fancy features.

This method is similar in spirit to the AbstractPropagator.propagate(org.orekit.time.AbsoluteDate) method, except that it does not call any handler during propagation, nor any discrete events. It always stop exactly at the specified date.

Overrides:

basicPropagate in class AbstractPropagator

Parameters:

date - target date for propagation

Returns:

state at specified date

Throws:

PropagationException - if propagation cannot reach specified date

propagateOrbit

protected Orbit propagateOrbit(AbsoluteDate date)
                        throws PropagationException

Extrapolate an orbit up to a specific target date.

Specified by:

propagateOrbit in class AbstractPropagator

Parameters:

date - target date for the orbit

Returns:

extrapolated parameters

Throws:

PropagationException - if some parameters are out of bounds

getPVCoordinates

public PVCoordinates getPVCoordinates(AbsoluteDate date,
                                      Frame frame)
                               throws OrekitException

Get the PVCoordinates of the body in the selected frame.

Specified by:

getPVCoordinates in interface PVCoordinatesProvider

Overrides:

getPVCoordinates in class AbstractPropagator

Parameters:

date - current date

frame - the frame where to define the position

Returns:

position/velocity of the body (m and m/s)

Throws:

OrekitException - if position cannot be computed in given frame

resetInitialState

public void resetInitialState(SpacecraftState state)
                       throws PropagationException

Try (and fail) to reset the initial state.

This method always throws an exception, as ephemerides cannot be reset.

Specified by:

resetInitialState in interface Propagator

Overrides:

resetInitialState in class AbstractPropagator

Parameters:

state - new initial state to consider

Throws:

PropagationException - always thrown as ephemerides cannot be reset

getInitialState

public SpacecraftState getInitialState()
                                throws PropagationException

Get the propagator initial state.

Specified by:

getInitialState in interface Propagator

Overrides:

getInitialState in class AbstractPropagator

Returns:

initial state

Throws:

PropagationException