org.orekit.propagation.numerical
Class NumericalPropagatorWithJacobians

java.lang.Object
  org.orekit.propagation.numerical.NumericalPropagator
      org.orekit.propagation.numerical.NumericalPropagatorWithJacobians

All Implemented Interfaces:

java.io.Serializable, BasicPropagator, Propagator, PVCoordinatesProvider

public class NumericalPropagatorWithJacobians
extends NumericalPropagator

This class propagates orbits using numerical integration and enables jacobians computation for orbit parameters and partial derivatives computation with respect to some force models parameters.

As of 5.0, this class is still considered experimental, so use it with care, the API could change in the future.

The underlying numerical integrator configuration can be exactly the same as these for a simple numerical integration.

The Jacobian for the six equinoctial orbit parameters (a, e_x, e_y, h_x, h_y, l_v) and the mass is computed as a 7x7 array such as:

     dFdY[i][j] = dyi/dyj
     with: y0 = a, y1 = ex, y2 = ey, y3 = hx, y4 = hy, y5 = lv, y6 = mass
   

Partial derivatives can also be computed for the 7 elements state vector with respect to n selected parameters from force models. They are computed as a 7xn array:

     dFdP[i][j] = dyi/dpj
   

Version:

$Revision: 3262 $ $Date: 2010-05-06 17:19:59 +0200 (jeu. 06 mai 2010) $

Author:

Pascal Parraud

See Also:

NumericalPropagator, ForceModelWithJacobians, Serialized Form

Field Summary

Fields inherited from class org.orekit.propagation.numerical.NumericalPropagator

attitudeLaw, calls, currentState, detectors, forceModels, initialState, integrator, mode, modeHandler, mu, startDate, stateVector

Fields inherited from interface org.orekit.propagation.Propagator

EPHEMERIS_GENERATION_MODE, MASTER_MODE, SLAVE_MODE

Constructor Summary

NumericalPropagatorWithJacobians(org.apache.commons.math.ode.FirstOrderIntegrator integrator)
Create a new instance of NumericalPropagatorWithJacobians.

Method Summary

void	addForceModel(ForceModel model) Add a force model to the global perturbation model.
java.lang.String[]	getParameterNames() Get the parameters selected for jacobian processing.
SpacecraftState	propagate(AbsoluteDate finalDate, double[][] dFdY, double[][] dFdP) Propagate towards a target date and compute partial derivatives.
void	removeForceModels() Remove all perturbing force models from the global perturbation model.
void	selectParameters(java.lang.String[] parameters) Select the parameters to consider for jacobian processing.

Methods inherited from class org.orekit.propagation.numerical.NumericalPropagator

addEventDetector, clearEventsDetectors, getCalls, getEventsDetectors, getGeneratedEphemeris, getInitialState, getMode, getMu, getPVCoordinates, propagate, resetInitialState, setAttitudeLaw, setEphemerisMode, setInitialState, setIntegrator, setMasterMode, setMasterMode, setMu, setSlaveMode, setUpEventDetector

Methods inherited from class java.lang.Object

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

Constructor Detail

NumericalPropagatorWithJacobians

public NumericalPropagatorWithJacobians(org.apache.commons.math.ode.FirstOrderIntegrator integrator)

Create a new instance of NumericalPropagatorWithJacobians. After creation, the instance is empty, i.e. the attitude law is set to an unspecified default law and there are no perturbing forces at all. This means that if addForceModel is not called after creation, the integrated orbit will follow a keplerian evolution only.

Parameters:

integrator - numerical integrator to use for propagation.

Method Detail

addForceModel

public void addForceModel(ForceModel model)

Add a force model to the global perturbation model.

Overrides:

addForceModel in class NumericalPropagator

Parameters:

model - perturbing force model to add

See Also:

removeForceModels(), removeForceModels()

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 keplerian evolution only.

Overrides:

removeForceModels in class NumericalPropagator

See Also:

addForceModel(ForceModel)

selectParameters

public void selectParameters(java.lang.String[] parameters)

Select the parameters to consider for jacobian processing.

Parameters names have to be consistent with some ForceModelWithJacobians added elsewhere.

Parameters:

parameters - parameters to consider for jacobian processing

See Also:

addForceModel(ForceModel), ForceModelWithJacobians, Parameterizable

getParameterNames

public java.lang.String[] getParameterNames()

Get the parameters selected for jacobian processing.

Returns:

parameters considered for jacobian processing

See Also:

selectParameters(String[])

propagate

public SpacecraftState propagate(AbsoluteDate finalDate,
                                 double[][] dFdY,
                                 double[][] dFdP)
                          throws PropagationException

Propagate towards a target date and compute partial derivatives.

Propagation is the same as the basic one.

Jacobian for orbit parameters is given as a 7x7 array.

Partial derivatives will be computed as a 7xn array when n parameters have been selected (n may be 0).

Those parameters are related to some force models which must have been added elsewhere.

Parameters:

finalDate - target date towards which orbit state should be propagated

dFdY - equinoctial orbit parameters + mass jacobian (7x7 array)

dFdP - partial derivatives with respect to selected parameters (7xn)

Returns:

propagated state

Throws:

PropagationException - if state cannot be propagated