Package org.orekit.forces.radiation

Class IsotropicRadiationCNES95Convention

java.lang.Object

org.orekit.forces.radiation.IsotropicRadiationCNES95Convention

All Implemented Interfaces:

RadiationSensitive

public class IsotropicRadiationCNES95Convention
extends Object
implements RadiationSensitive

This class represents the features of a simplified spacecraft.

This model uses the coefficients described in the collective book edited by CNES in 1995: Spaceflight Dynamics (part I), in section 5.2.2.1.3.1 (page 296 of the English edition). The absorption coefficient is called α and the specular reflection coefficient is called τ. A comment in section 5.2.2.1.3.2 of the same book reads:

 Some authors prefer to express thermo-optical properties for surfaces
 using the following coefficients: Ka = α, Ks = (1-α)τ, Kd = (1-α)(1-τ)
 

Ka is the same absorption coefficient, and Ks is also called specular reflection coefficient, which leads to a confusion. In fact, as the Ka, Ks and Kd coefficients are the most frequently used ones (using the names Ca, Cs and Cd), when speaking about reflection coefficients, it is more often Cd that is considered rather than τ.

The classical set of coefficients Ca, Cs, and Cd are implemented in the sister class IsotropicRadiationClassicalConvention, which should probably be preferred to this legacy class.

Since:

7.1

Author:

Luc Maisonobe

See Also:

BoxAndSolarArraySpacecraft, IsotropicDrag, IsotropicRadiationClassicalConvention

Field Summary

Fields inherited from interface org.orekit.forces.radiation.RadiationSensitive

ABSORPTION_COEFFICIENT, REFLECTION_COEFFICIENT

Constructor Summary

Constructors

Constructor	Description
IsotropicRadiationCNES95Convention(double crossSection, double alpha, double tau)	Simple constructor.

Method Summary

Modifier and Type	Method	Description
ParameterDriver[]	getRadiationParametersDrivers()	Get the drivers for supported parameters.
Vector3D	radiationPressureAcceleration(AbsoluteDate date, Frame frame, Vector3D position, Rotation rotation, double mass, Vector3D flux, double[] parameters)	Compute the acceleration due to radiation pressure.
FieldVector3D<DerivativeStructure>	radiationPressureAcceleration(AbsoluteDate date, Frame frame, Vector3D position, Rotation rotation, double mass, Vector3D flux, double[] parameters, String paramName)	Compute the acceleration due to radiation pressure, with parameters derivatives.
<T extends RealFieldElement<T>> FieldVector3D<T>	radiationPressureAcceleration(FieldAbsoluteDate<T> date, Frame frame, FieldVector3D<T> position, FieldRotation<T> rotation, T mass, FieldVector3D<T> flux, T[] parameters)	Compute the acceleration due to radiation pressure.

Methods inherited from class java.lang.Object

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

Constructor Detail

IsotropicRadiationCNES95Convention

public IsotropicRadiationCNES95Convention(double crossSection,
                                          double alpha,
                                          double tau)

Simple constructor.

Parameters:

crossSection - Surface (m²)

alpha - absorption coefficient α between 0.0 an 1.0

tau - specular reflection coefficient τ between 0.0 an 1.0

Method Detail

getRadiationParametersDrivers

public ParameterDriver[] getRadiationParametersDrivers()

Get the drivers for supported parameters.

Specified by:

getRadiationParametersDrivers in interface RadiationSensitive

Returns:

parameters drivers

radiationPressureAcceleration

public Vector3D radiationPressureAcceleration(AbsoluteDate date,
                                              Frame frame,
                                              Vector3D position,
                                              Rotation rotation,
                                              double mass,
                                              Vector3D flux,
                                              double[] parameters)

Compute the acceleration due to radiation pressure.

Specified by:

radiationPressureAcceleration in interface RadiationSensitive

Parameters:

date - current date

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

position - position of spacecraft in reference frame

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

mass - current mass

flux - radiation flux in the same inertial frame as spacecraft orbit

parameters - values of the force model parameters

Returns:

spacecraft acceleration in the same inertial frame as spacecraft orbit (m/s²)

radiationPressureAcceleration

public <T extends RealFieldElement<T>> FieldVector3D<T> radiationPressureAcceleration(FieldAbsoluteDate<T> date,
                                                                                      Frame frame,
                                                                                      FieldVector3D<T> position,
                                                                                      FieldRotation<T> rotation,
                                                                                      T mass,
                                                                                      FieldVector3D<T> flux,
                                                                                      T[] parameters)
                                                                               throws OrekitException

Compute the acceleration due to radiation pressure.

Specified by:

radiationPressureAcceleration in interface RadiationSensitive

Type Parameters:

T - extends RealFieldElement

Parameters:

date - current date

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

position - position of spacecraft in reference frame

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

mass - current mass

flux - radiation flux in the same inertial frame as spacecraft orbit

parameters - values of the force model parameters

Returns:

spacecraft acceleration in the same inertial frame as spacecraft orbit (m/s²)

Throws:

OrekitException - if acceleration cannot be computed

radiationPressureAcceleration

public FieldVector3D<DerivativeStructure> radiationPressureAcceleration(AbsoluteDate date,
                                                                        Frame frame,
                                                                        Vector3D position,
                                                                        Rotation rotation,
                                                                        double mass,
                                                                        Vector3D flux,
                                                                        double[] parameters,
                                                                        String paramName)
                                                                 throws OrekitException

Compute the acceleration due to radiation pressure, with parameters derivatives.

Specified by:

radiationPressureAcceleration in interface RadiationSensitive

Parameters:

date - current date

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

position - position of spacecraft in reference frame

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

mass - current mass

flux - radiation flux in the same inertial frame as spacecraft orbit

parameters - values of the force model parameters

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

Returns:

spacecraft acceleration in the same inertial frame as spacecraft orbit (m/s²)

Throws:

OrekitException - if acceleration cannot be computed