Package org.orekit.propagation.analytical.gnss

Class GNSSPropagator

java.lang.Object

org.orekit.propagation.AbstractPropagator

org.orekit.propagation.analytical.AbstractAnalyticalPropagator

org.orekit.propagation.analytical.gnss.GNSSPropagator

All Implemented Interfaces:

Propagator, PVCoordinatesProvider

public class GNSSPropagator
extends AbstractAnalyticalPropagator

Common handling of AbstractAnalyticalPropagator methods for GNSS propagators.

This class allows to provide easily a subset of AbstractAnalyticalPropagator methods for specific GNSS propagators.

Author:

Pascal Parraud

Field Summary

Fields inherited from interface org.orekit.propagation.Propagator

DEFAULT_MASS

Method Summary

Modifier and Type	Method	Description
protected AbstractMatricesHarvester	createHarvester(String stmName, RealMatrix initialStm, DoubleArrayDictionary initialJacobianColumns)	Create the harvester suitable for propagator.
Frame	getECEF()	Gets the Earth Centered Earth Fixed frame used to propagate GNSS orbits according to the Interface Control Document.
Frame	getECI()	Gets the Earth Centered Inertial frame used to propagate the orbit.
Frame	getFrame()	Get the frame in which the orbit is propagated.
protected List<String>	getJacobiansColumnsNames()	Get the names of the parameters in the matrix returned by MatricesHarvester.getParametersJacobian(org.orekit.propagation.SpacecraftState).
protected double	getMass(AbsoluteDate date)	Get the mass.
double	getMU()	Gets the Earth gravity coefficient used for GNSS propagation.
GNSSOrbitalElements<?>	getOrbitalElements()	Get the underlying GNSS propagation orbital elements.
PVCoordinates	propagateInEcef(AbsoluteDate date)	Gets the PVCoordinates of the GNSS SV in ECEF frame.
protected Orbit	propagateOrbit(AbsoluteDate date)	Extrapolate an orbit up to a specific target date.
void	resetInitialState(SpacecraftState state)	Reset the propagator initial state.
protected void	resetIntermediateState(SpacecraftState state, boolean forward)	Reset an intermediate state.

Methods inherited from class org.orekit.propagation.analytical.AbstractAnalyticalPropagator

acceptStep, addEventDetector, basicPropagate, clearEventsDetectors, getEphemerisGenerator, getEventDetectors, getPvProvider, propagate

Methods inherited from class org.orekit.propagation.AbstractPropagator

addAdditionalStateProvider, getAdditionalStateProviders, getAttitudeProvider, getHarvester, getInitialState, getManagedAdditionalStates, getMultiplexer, getStartDate, initializeAdditionalStates, initializePropagation, isAdditionalStateManaged, propagate, setAttitudeProvider, setStartDate, setupMatricesComputation, stateChanged, updateAdditionalStates, updateUnmanagedStates

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

clearStepHandlers, getPosition, getPVCoordinates, setStepHandler, setStepHandler

Method Detail

getECI

public Frame getECI()

Gets the Earth Centered Inertial frame used to propagate the orbit.

Returns:

the ECI frame

getECEF

public Frame getECEF()

Gets the Earth Centered Earth Fixed frame used to propagate GNSS orbits according to the Interface Control Document.

Returns:

the ECEF frame

getMU

public double getMU()

Gets the Earth gravity coefficient used for GNSS propagation.

Returns:

the Earth gravity coefficient.

getOrbitalElements

public GNSSOrbitalElements<?> getOrbitalElements()

Get the underlying GNSS propagation orbital elements.

Returns:

the underlying GNSS orbital elements

Since:

13.0

createHarvester

protected AbstractMatricesHarvester createHarvester(String stmName,
                                                    RealMatrix initialStm,
                                                    DoubleArrayDictionary initialJacobianColumns)

Create the harvester suitable for propagator.

Overrides:

createHarvester in class AbstractPropagator

Parameters:

stmName - State Transition Matrix state name

initialStm - initial State Transition Matrix ∂Y/∂Y₀, if null (which is the most frequent case), assumed to be 6x6 identity

initialJacobianColumns - initial columns of the Jacobians matrix with respect to parameters, if null or if some selected parameters are missing from the dictionary, the corresponding initial column is assumed to be 0

Returns:

harvester to retrieve computed matrices during and after propagation

Since:

13.0

getJacobiansColumnsNames

protected List<String> getJacobiansColumnsNames()

Get the names of the parameters in the matrix returned by MatricesHarvester.getParametersJacobian(org.orekit.propagation.SpacecraftState).

Overrides:

getJacobiansColumnsNames in class AbstractAnalyticalPropagator

Returns:

names of the parameters (i.e. columns) of the Jacobian matrix

Since:

13.0

propagateOrbit

protected Orbit propagateOrbit(AbsoluteDate date)

Extrapolate an orbit up to a specific target date.

Specified by:

propagateOrbit in class AbstractAnalyticalPropagator

Parameters:

date - target date for the orbit

Returns:

extrapolated parameters

propagateInEcef

public PVCoordinates propagateInEcef(AbsoluteDate date)

Gets the PVCoordinates of the GNSS SV in ECEF frame.

The algorithm uses automatic differentiation to compute velocity and acceleration.

Parameters:

date - the computation date

Returns:

the GNSS SV PVCoordinates in ECEF frame

getFrame

public Frame getFrame()

Get the frame in which the orbit is propagated.

The propagation frame is the definition frame of the initial state, so this method should be called after this state has been set, otherwise it may return null.

Specified by:

getFrame in interface Propagator

Overrides:

getFrame in class AbstractPropagator

Returns:

frame in which the orbit is propagated

See Also:

Propagator.resetInitialState(SpacecraftState)

getMass

protected double getMass(AbsoluteDate date)

Get the mass.

Specified by:

getMass in class AbstractAnalyticalPropagator

Parameters:

date - target date for the orbit

Returns:

mass mass

resetInitialState

public void resetInitialState(SpacecraftState state)

Reset the propagator initial state.

Specified by:

resetInitialState in interface Propagator

Overrides:

resetInitialState in class AbstractPropagator

Parameters:

state - new initial state to consider

resetIntermediateState

protected void resetIntermediateState(SpacecraftState state,
                                      boolean forward)

Reset an intermediate state.

Specified by:

resetIntermediateState in class AbstractAnalyticalPropagator

Parameters:

state - new intermediate state to consider

forward - if true, the intermediate state is valid for propagations after itself