org.orekit.forces

Class BoxAndSolarArraySpacecraft

java.lang.Object

org.orekit.forces.BoxAndSolarArraySpacecraft

All Implemented Interfaces:

DragSensitive, RadiationSensitive

public class BoxAndSolarArraySpacecraft
extends Object
implements RadiationSensitive, DragSensitive

experimental class representing the features of a classical satellite with a convex body shape and rotating flat solar arrays.

As of 5.0, this class is still considered experimental, so use it with care.

The body can be either a simple parallelepipedic box aligned with spacecraft axes or a set of facets defined by their area and normal vector. This should handle accurately most spacecraft shapes.

The solar array rotation with respect to satellite body can be either the best lightning orientation (i.e. Sun exactly in solar array meridian plane defined by solar array rotation axis and solar array normal vector) or a rotation evolving linearly according to a start position and an angular rate (which can be set to 0 for non-rotating panels, which may occur in special modes or during contingencies).

This model does not take cast shadow between body and solar array into account.

Instances of this class are guaranteed to be immutable.

Author:

Luc Maisonobe, Pascal Parraud

See Also:

SphericalSpacecraft

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BoxAndSolarArraySpacecraft.Facet Class representing a single facet of a convex spacecraft body.

Field Summary

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

ABSORPTION_COEFFICIENT, REFLECTION_COEFFICIENT

Fields inherited from interface org.orekit.forces.drag.DragSensitive

DRAG_COEFFICIENT

Constructor Summary

Constructors

Constructor and Description
BoxAndSolarArraySpacecraft(BoxAndSolarArraySpacecraft.Facet[] facets, PVCoordinatesProvider sun, double solarArrayArea, Vector3D solarArrayAxis, AbsoluteDate referenceDate, Vector3D referenceNormal, double rotationRate, double dragCoeff, double absorptionCoeff, double reflectionCoeff) Build a spacecraft model with linear rotation of solar array.
BoxAndSolarArraySpacecraft(BoxAndSolarArraySpacecraft.Facet[] facets, PVCoordinatesProvider sun, double solarArrayArea, Vector3D solarArrayAxis, double dragCoeff, double absorptionCoeff, double reflectionCoeff) Build a spacecraft model with best lightning of solar array.
BoxAndSolarArraySpacecraft(double xLength, double yLength, double zLength, PVCoordinatesProvider sun, double solarArrayArea, Vector3D solarArrayAxis, AbsoluteDate referenceDate, Vector3D referenceNormal, double rotationRate, double dragCoeff, double absorptionCoeff, double reflectionCoeff) Build a spacecraft model with linear rotation of solar array.
BoxAndSolarArraySpacecraft(double xLength, double yLength, double zLength, PVCoordinatesProvider sun, double solarArrayArea, Vector3D solarArrayAxis, double dragCoeff, double absorptionCoeff, double reflectionCoeff) Build a spacecraft model with best lightning of solar array.

Method Summary

Methods

Modifier and Type	Method and Description
FieldVector3D<DerivativeStructure>	dragAcceleration(AbsoluteDate date, Frame frame, FieldVector3D<DerivativeStructure> position, FieldRotation<DerivativeStructure> rotation, DerivativeStructure mass, double density, FieldVector3D<DerivativeStructure> relativeVelocity) Compute the acceleration due to drag, with state derivatives.
Vector3D	dragAcceleration(AbsoluteDate date, Frame frame, Vector3D position, Rotation rotation, double mass, double density, Vector3D relativeVelocity) Compute the acceleration due to drag.
FieldVector3D<DerivativeStructure>	dragAcceleration(AbsoluteDate date, Frame frame, Vector3D position, Rotation rotation, double mass, double density, Vector3D relativeVelocity, String paramName) Compute acceleration due to drag, with parameters derivatives.
double	getAbsorptionCoefficient() Get the absorption coefficient.
double	getDragCoefficient() Get the drag coefficient.
FieldVector3D<DerivativeStructure>	getNormal(AbsoluteDate date, Frame frame, FieldVector3D<DerivativeStructure> position, FieldRotation<DerivativeStructure> rotation) Get solar array normal in spacecraft frame.
Vector3D	getNormal(AbsoluteDate date, Frame frame, Vector3D position, Rotation rotation) Get solar array normal in spacecraft frame.
double	getReflectionCoefficient() Get the specular reflection coefficient.
FieldVector3D<DerivativeStructure>	radiationPressureAcceleration(AbsoluteDate date, Frame frame, FieldVector3D<DerivativeStructure> position, FieldRotation<DerivativeStructure> rotation, DerivativeStructure mass, FieldVector3D<DerivativeStructure> flux) Compute the acceleration due to radiation pressure, with state derivatives.
Vector3D	radiationPressureAcceleration(AbsoluteDate date, Frame frame, Vector3D position, Rotation rotation, double mass, Vector3D flux) Compute the acceleration due to radiation pressure.
FieldVector3D<DerivativeStructure>	radiationPressureAcceleration(AbsoluteDate date, Frame frame, Vector3D position, Rotation rotation, double mass, Vector3D flux, String paramName) Compute the acceleration due to radiation pressure, with parameters derivatives.
void	setAbsorptionCoefficient(double value) Set the absorption coefficient.
void	setDragCoefficient(double value) Set the drag coefficient.
void	setReflectionCoefficient(double value) Set the specular reflection coefficient.

Methods inherited from class java.lang.Object

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

Constructor Detail

BoxAndSolarArraySpacecraft

public BoxAndSolarArraySpacecraft(double xLength,
                          double yLength,
                          double zLength,
                          PVCoordinatesProvider sun,
                          double solarArrayArea,
                          Vector3D solarArrayAxis,
                          double dragCoeff,
                          double absorptionCoeff,
                          double reflectionCoeff)

Build a spacecraft model with best lightning of solar array.

Solar arrays orientation will be such that at each time the Sun direction will always be in the solar array meridian plane defined by solar array rotation axis and solar array normal vector.

Parameters:

xLength - length of the body along its X axis (m)

yLength - length of the body along its Y axis (m)

zLength - length of the body along its Z axis (m)

sun - sun model

solarArrayArea - area of the solar array (m²)

solarArrayAxis - solar array rotation axis in satellite frame

dragCoeff - drag coefficient (used only for drag)

absorptionCoeff - absorption coefficient between 0.0 an 1.0 (used only for radiation pressure)

reflectionCoeff - specular reflection coefficient between 0.0 an 1.0 (used only for radiation pressure)

BoxAndSolarArraySpacecraft

public BoxAndSolarArraySpacecraft(BoxAndSolarArraySpacecraft.Facet[] facets,
                          PVCoordinatesProvider sun,
                          double solarArrayArea,
                          Vector3D solarArrayAxis,
                          double dragCoeff,
                          double absorptionCoeff,
                          double reflectionCoeff)

Build a spacecraft model with best lightning of solar array.

The spacecraft body is described by an array of surface vectors. Each facet of the body is describe by a vector normal to the facet (pointing outward of the spacecraft) and whose norm is the surface area in m².

Solar arrays orientation will be such that at each time the Sun direction will always be in the solar array meridian plane defined by solar array rotation axis and solar array normal vector.

Parameters:

facets - body facets (only the facets with strictly positive area will be stored)

sun - sun model

solarArrayArea - area of the solar array (m²)

solarArrayAxis - solar array rotation axis in satellite frame

dragCoeff - drag coefficient (used only for drag)

absorptionCoeff - absorption coefficient between 0.0 an 1.0 (used only for radiation pressure)

reflectionCoeff - specular reflection coefficient between 0.0 an 1.0 (used only for radiation pressure)

BoxAndSolarArraySpacecraft

public BoxAndSolarArraySpacecraft(double xLength,
                          double yLength,
                          double zLength,
                          PVCoordinatesProvider sun,
                          double solarArrayArea,
                          Vector3D solarArrayAxis,
                          AbsoluteDate referenceDate,
                          Vector3D referenceNormal,
                          double rotationRate,
                          double dragCoeff,
                          double absorptionCoeff,
                          double reflectionCoeff)

Build a spacecraft model with linear rotation of solar array.

Solar arrays orientation will be a regular rotation from the reference orientation at reference date and using a constant rotation rate.

Parameters:

xLength - length of the body along its X axis (m)

yLength - length of the body along its Y axis (m)

zLength - length of the body along its Z axis (m)

sun - sun model

solarArrayArea - area of the solar array (m²)

solarArrayAxis - solar array rotation axis in satellite frame

referenceDate - reference date for the solar array rotation

referenceNormal - direction of the solar array normal at reference date in spacecraft frame

rotationRate - rotation rate of the solar array, may be 0 (rad/s)

dragCoeff - drag coefficient (used only for drag)

absorptionCoeff - absorption coefficient between 0.0 an 1.0 (used only for radiation pressure)

reflectionCoeff - specular reflection coefficient between 0.0 an 1.0 (used only for radiation pressure)

BoxAndSolarArraySpacecraft

public BoxAndSolarArraySpacecraft(BoxAndSolarArraySpacecraft.Facet[] facets,
                          PVCoordinatesProvider sun,
                          double solarArrayArea,
                          Vector3D solarArrayAxis,
                          AbsoluteDate referenceDate,
                          Vector3D referenceNormal,
                          double rotationRate,
                          double dragCoeff,
                          double absorptionCoeff,
                          double reflectionCoeff)

Build a spacecraft model with linear rotation of solar array.

The spacecraft body is described by an array of surface vectors. Each facet of the body is describe by a vector normal to the facet (pointing outward of the spacecraft) and whose norm is the surface area in m².

Solar arrays orientation will be a regular rotation from the reference orientation at reference date and using a constant rotation rate.

Parameters:

facets - body facets (only the facets with strictly positive area will be stored)

sun - sun model

solarArrayArea - area of the solar array (m²)

solarArrayAxis - solar array rotation axis in satellite frame

referenceDate - reference date for the solar array rotation

referenceNormal - direction of the solar array normal at reference date in spacecraft frame

rotationRate - rotation rate of the solar array, may be 0 (rad/s)

dragCoeff - drag coefficient (used only for drag)

absorptionCoeff - absorption coefficient between 0.0 an 1.0 (used only for radiation pressure)

reflectionCoeff - specular reflection coefficient between 0.0 an 1.0 (used only for radiation pressure)

Method Detail

getNormal

public Vector3D getNormal(AbsoluteDate date,
                 Frame frame,
                 Vector3D position,
                 Rotation rotation)
                   throws OrekitException

Get solar array normal in spacecraft frame.

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

Returns:

solar array normal in spacecraft frame

Throws:

OrekitException - if sun direction cannot be computed in best lightning configuration

getNormal

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

Get solar array normal in spacecraft frame.

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

Returns:

solar array normal in spacecraft frame

Throws:

OrekitException - if sun direction cannot be computed in best lightning configuration

dragAcceleration

public Vector3D dragAcceleration(AbsoluteDate date,
                        Frame frame,
                        Vector3D position,
                        Rotation rotation,
                        double mass,
                        double density,
                        Vector3D relativeVelocity)
                          throws OrekitException

Compute the acceleration due to drag.

The computation includes all spacecraft specific characteristics like shape, area and coefficients.

Specified by:

dragAcceleration in interface DragSensitive

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

density - atmospheric density at spacecraft position

relativeVelocity - relative velocity of atmosphere with respect to spacecraft, in the same inertial frame as spacecraft orbit (m/s)

Returns:

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

Throws:

OrekitException - if acceleration cannot be computed

dragAcceleration

public FieldVector3D<DerivativeStructure> dragAcceleration(AbsoluteDate date,
                                                  Frame frame,
                                                  FieldVector3D<DerivativeStructure> position,
                                                  FieldRotation<DerivativeStructure> rotation,
                                                  DerivativeStructure mass,
                                                  double density,
                                                  FieldVector3D<DerivativeStructure> relativeVelocity)
                                                    throws OrekitException

Compute the acceleration due to drag, with state derivatives.

The computation includes all spacecraft specific characteristics like shape, area and coefficients.

Specified by:

dragAcceleration in interface DragSensitive

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 - spacecraft mass

density - atmospheric density at spacecraft position

relativeVelocity - relative velocity of atmosphere with respect to spacecraft, in the same inertial frame as spacecraft orbit (m/s)

Returns:

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

Throws:

OrekitException - if acceleration cannot be computed

dragAcceleration

public FieldVector3D<DerivativeStructure> dragAcceleration(AbsoluteDate date,
                                                  Frame frame,
                                                  Vector3D position,
                                                  Rotation rotation,
                                                  double mass,
                                                  double density,
                                                  Vector3D relativeVelocity,
                                                  String paramName)
                                                    throws OrekitException

Compute acceleration due to drag, with parameters derivatives.

Specified by:

dragAcceleration in interface DragSensitive

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

density - atmospheric density at spacecraft position

relativeVelocity - relative velocity of atmosphere with respect to spacecraft, in the same inertial frame as spacecraft orbit (m/s)

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 derivatives cannot be computed

radiationPressureAcceleration

public Vector3D radiationPressureAcceleration(AbsoluteDate date,
                                     Frame frame,
                                     Vector3D position,
                                     Rotation rotation,
                                     double mass,
                                     Vector3D flux)
                                       throws OrekitException

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

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,
                                                               FieldVector3D<DerivativeStructure> position,
                                                               FieldRotation<DerivativeStructure> rotation,
                                                               DerivativeStructure mass,
                                                               FieldVector3D<DerivativeStructure> flux)
                                                                 throws OrekitException

Compute the acceleration due to radiation pressure, with state 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 - spacecraft mass

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

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,
                                                               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

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

setAbsorptionCoefficient

public void setAbsorptionCoefficient(double value)

Set the absorption coefficient.

Specified by:

setAbsorptionCoefficient in interface RadiationSensitive

Parameters:

value - absorption coefficient

getAbsorptionCoefficient

public double getAbsorptionCoefficient()

Get the absorption coefficient.

Specified by:

getAbsorptionCoefficient in interface RadiationSensitive

Returns:

absorption coefficient

setReflectionCoefficient

public void setReflectionCoefficient(double value)

Set the specular reflection coefficient.

Specified by:

setReflectionCoefficient in interface RadiationSensitive

Parameters:

value - specular reflection coefficient

getReflectionCoefficient

public double getReflectionCoefficient()

Get the specular reflection coefficient.

Specified by:

getReflectionCoefficient in interface RadiationSensitive

Returns:

reflection coefficient

setDragCoefficient

public void setDragCoefficient(double value)

Set the drag coefficient.

Specified by:

setDragCoefficient in interface DragSensitive

Parameters:

value - drag coefficient

getDragCoefficient

public double getDragCoefficient()

Get the drag coefficient.

Specified by:

getDragCoefficient in interface DragSensitive

Returns:

drag coefficient