org.orekit.forces.gravity

Class NewtonianAttraction

java.lang.Object

org.orekit.forces.AbstractForceModel

org.orekit.forces.gravity.NewtonianAttraction

All Implemented Interfaces:

ForceModel

public class NewtonianAttraction
extends AbstractForceModel

Force model for Newtonian central body attraction.

Author:

Luc Maisonobe

Field Summary

Fields

Modifier and Type	Field and Description
static String	CENTRAL_ATTRACTION_COEFFICIENT Name of the single parameter of this model: the central attraction coefficient.

Constructor Summary

Constructors

Constructor and Description
NewtonianAttraction(double mu) Simple constructor.

Method Summary

Modifier and Type	Method and Description
org.hipparchus.geometry.euclidean.threed.FieldVector3D<org.hipparchus.analysis.differentiation.DerivativeStructure>	accelerationDerivatives(AbsoluteDate date, Frame frame, org.hipparchus.geometry.euclidean.threed.FieldVector3D<org.hipparchus.analysis.differentiation.DerivativeStructure> position, org.hipparchus.geometry.euclidean.threed.FieldVector3D<org.hipparchus.analysis.differentiation.DerivativeStructure> velocity, org.hipparchus.geometry.euclidean.threed.FieldRotation<org.hipparchus.analysis.differentiation.DerivativeStructure> rotation, org.hipparchus.analysis.differentiation.DerivativeStructure mass) Compute acceleration derivatives with respect to state parameters.
org.hipparchus.geometry.euclidean.threed.FieldVector3D<org.hipparchus.analysis.differentiation.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	getMu() Get the central attraction coefficient μ.
ParameterDriver[]	getParametersDrivers() Get the drivers for force model parameters.

Methods inherited from class org.orekit.forces.AbstractForceModel

complainIfNotSupported, getParameter, getParameterDriver, getParametersNames, isSupported, setParameter

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.orekit.forces.ForceModel

init

Field Detail

CENTRAL_ATTRACTION_COEFFICIENT

public static final String CENTRAL_ATTRACTION_COEFFICIENT

Name of the single parameter of this model: the central attraction coefficient.

See Also:

Constant Field Values

Constructor Detail

NewtonianAttraction

public NewtonianAttraction(double mu)

Simple constructor.

Parameters:

mu - central attraction coefficient (m^3/s^2)

Method Detail

accelerationDerivatives

public org.hipparchus.geometry.euclidean.threed.FieldVector3D<org.hipparchus.analysis.differentiation.DerivativeStructure> accelerationDerivatives(AbsoluteDate date,
                                                                                                                                                   Frame frame,
                                                                                                                                                   org.hipparchus.geometry.euclidean.threed.FieldVector3D<org.hipparchus.analysis.differentiation.DerivativeStructure> position,
                                                                                                                                                   org.hipparchus.geometry.euclidean.threed.FieldVector3D<org.hipparchus.analysis.differentiation.DerivativeStructure> velocity,
                                                                                                                                                   org.hipparchus.geometry.euclidean.threed.FieldRotation<org.hipparchus.analysis.differentiation.DerivativeStructure> rotation,
                                                                                                                                                   org.hipparchus.analysis.differentiation.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.

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 org.hipparchus.geometry.euclidean.threed.FieldVector3D<org.hipparchus.analysis.differentiation.DerivativeStructure> accelerationDerivatives(SpacecraftState s,
                                                                                                                                                   String paramName)
                                                                                                                                            throws OrekitException

Compute acceleration derivatives with respect to additional parameters.

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

getMu

public double getMu()

Get the central attraction coefficient μ.

Returns:

mu central attraction coefficient (m³/s²)

addContribution

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

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

Parameters:

s - current state information: date, kinematics, attitude

adder - object where the contribution should be added

Throws:

OrekitException - if some specific error occurs

getEventsDetectors

public EventDetector[] getEventsDetectors()

Get the discrete events related to the model.

Returns:

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

getParametersDrivers

public ParameterDriver[] getParametersDrivers()

Get the drivers for force model parameters.

Returns:

drivers for force model parameters