org.orekit.forces.gravity

Class OceanTides

java.lang.Object

org.apache.commons.math3.ode.AbstractParameterizable

org.orekit.forces.gravity.OceanTides

All Implemented Interfaces:

Parameterizable, ParameterizedODE, ForceModel

public class OceanTides
extends AbstractParameterizable
implements ForceModel

Ocean tides force model.

Since:

6.1

Author:

Luc Maisonobe

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_POINTS Default number of points tides field sampling.
static double	DEFAULT_STEP Default step for tides field sampling (seconds).

Constructor Summary

Constructors

Constructor and Description
OceanTides(Frame centralBodyFrame, double ae, double mu, boolean poleTide, double step, int nbPoints, int degree, int order, IERSConventions conventions, UT1Scale ut1) Simple constructor.
OceanTides(Frame centralBodyFrame, double ae, double mu, int degree, int order, IERSConventions conventions, UT1Scale ut1) Simple constructor.

Method Summary

Methods

Modifier and Type	Method and Description
FieldVector3D<DerivativeStructure>	accelerationDerivatives(AbsoluteDate date, Frame frame, FieldVector3D<DerivativeStructure> position, FieldVector3D<DerivativeStructure> velocity, FieldRotation<DerivativeStructure> rotation, DerivativeStructure mass) Compute acceleration derivatives with respect to state parameters.
FieldVector3D<DerivativeStructure>	accelerationDerivatives(SpacecraftState s, String paramName) Compute acceleration derivatives with respect to additional parameters.
void	addContribution(SpacecraftState s, TimeDerivativesEquations adder) Compute the contribution of the force model to the perturbing acceleration.
EventDetector[]	getEventsDetectors() Get the discrete events related to the model.
double	getParameter(String name)
void	setParameter(String name, double value)

Methods inherited from class org.apache.commons.math3.ode.AbstractParameterizable

complainIfNotSupported, getParametersNames, isSupported

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.commons.math3.ode.Parameterizable

getParametersNames, isSupported

Field Detail

DEFAULT_STEP

public static final double DEFAULT_STEP

Default step for tides field sampling (seconds).

See Also:

Constant Field Values

DEFAULT_POINTS

public static final int DEFAULT_POINTS

Default number of points tides field sampling.

See Also:

Constant Field Values

Constructor Detail

OceanTides

public OceanTides(Frame centralBodyFrame,
          double ae,
          double mu,
          int degree,
          int order,
          IERSConventions conventions,
          UT1Scale ut1)
           throws OrekitException

Simple constructor.

This constructor uses pole tides, the default step and default number of points for the tides field interpolation.

Parameters:

centralBodyFrame - rotating body frame

ae - central body reference radius

mu - central body attraction coefficient

degree - degree of the tide model to load

order - order of the tide model to load

conventions - IERS conventions used for loading ocean pole tide

ut1 - UT1 time scale

Throws:

OrekitException - if the ocean tides model cannot be read or the model does not support requested degree or order

See Also:

DEFAULT_STEP, DEFAULT_POINTS, OceanTides(Frame, double, double, boolean, double, int, int, int, IERSConventions, UT1Scale), GravityFieldFactory.getOceanTidesWaves(int, int)

OceanTides

public OceanTides(Frame centralBodyFrame,
          double ae,
          double mu,
          boolean poleTide,
          double step,
          int nbPoints,
          int degree,
          int order,
          IERSConventions conventions,
          UT1Scale ut1)
           throws OrekitException

Simple constructor.

Parameters:

centralBodyFrame - rotating body frame

ae - central body reference radius

mu - central body attraction coefficient

poleTide - if true, pole tide is computed

step - time step between sample points for interpolation

nbPoints - number of points to use for interpolation, if less than 2 then no interpolation is performed (thus greatly increasing computation cost)

degree - degree of the tide model to load

order - order of the tide model to load

conventions - IERS conventions used for loading ocean pole tide

ut1 - UT1 time scale

Throws:

OrekitException - if the ocean tides model cannot be read or the model does not support requested degree or order

See Also:

GravityFieldFactory.getOceanTidesWaves(int, int)

Method Detail

getParameter

public double getParameter(String name)
                    throws UnknownParameterException

Specified by:

getParameter in interface ParameterizedODE

Throws:

UnknownParameterException

setParameter

public void setParameter(String name,
                double value)
                  throws UnknownParameterException

Specified by:

setParameter in interface ParameterizedODE

Throws:

UnknownParameterException

addContribution

public void addContribution(SpacecraftState s,
                   TimeDerivativesEquations adder)
                     throws OrekitException

Compute the contribution of the force model to the perturbing acceleration.

Specified by:

addContribution in interface ForceModel

Parameters:

s - current state information: date, kinematics, attitude

adder - object where the contribution should be added

Throws:

OrekitException - if some specific error occurs

accelerationDerivatives

public FieldVector3D<DerivativeStructure> accelerationDerivatives(AbsoluteDate date,
                                                         Frame frame,
                                                         FieldVector3D<DerivativeStructure> position,
                                                         FieldVector3D<DerivativeStructure> velocity,
                                                         FieldRotation<DerivativeStructure> rotation,
                                                         DerivativeStructure mass)
                                                           throws OrekitException

Compute acceleration derivatives with respect to state parameters.

The derivatives should be computed with respect to position, velocity and optionnaly mass. The input parameters already take into account the free parameters (6 or 7 depending on derivation with respect to mass being considered or not) and order (always 1). Free parameters at indices 0, 1 and 2 correspond to derivatives with respect to position. Free parameters at indices 3, 4 and 5 correspond to derivatives with respect to velocity. Free parameter at index 6 (if present) corresponds to to derivatives with respect to mass.

Specified by:

accelerationDerivatives in interface ForceModel

Parameters:

date - current date

frame - inertial reference frame for state (both orbit and attitude)

position - position of spacecraft in reference frame

velocity - velocity of spacecraft in reference frame

rotation - orientation (attitude) of the spacecraft with respect to reference frame

mass - spacecraft mass

Returns:

acceleration with all derivatives specified by the input parameters own derivatives

Throws:

OrekitException - if derivatives cannot be computed

accelerationDerivatives

public FieldVector3D<DerivativeStructure> accelerationDerivatives(SpacecraftState s,
                                                         String paramName)
                                                           throws OrekitException

Compute acceleration derivatives with respect to additional parameters.

Specified by:

accelerationDerivatives in interface ForceModel

Parameters:

s - spacecraft state

paramName - name of the parameter with respect to which derivatives are required

Returns:

acceleration with all derivatives specified by the input parameters own derivatives

Throws:

OrekitException - if derivatives cannot be computed

getEventsDetectors

public EventDetector[] getEventsDetectors()

Get the discrete events related to the model.

Specified by:

getEventsDetectors in interface ForceModel

Returns:

array of events detectors or null if the model is not related to any discrete events