Package org.orekit.forces.drag

Class IsotropicDrag

java.lang.Object

org.orekit.forces.drag.IsotropicDrag

All Implemented Interfaces:

DragSensitive

public class IsotropicDrag
extends Object
implements DragSensitive

This class models isotropic drag effects.

The model of this spacecraft is a simple spherical model, this means that all coefficients are constant and do not depend of the direction.

Since:

7.1

Author:

Luc Maisonobe

See Also:

BoxAndSolarArraySpacecraft, IsotropicRadiationCNES95Convention

Field Summary

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

DRAG_COEFFICIENT, LIFT_RATIO

Constructor Summary

Constructors

Constructor	Description
IsotropicDrag(double crossSection, double dragCoeff)	Constructor with drag coefficient min/max set to ±∞.
IsotropicDrag(double crossSection, double dragCoeff, double dragCoeffMin, double dragCoeffMax)	Constructor with drag coefficient min/max set by user.

Method Summary

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

Methods inherited from class java.lang.Object

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

Constructor Detail

IsotropicDrag

public IsotropicDrag(double crossSection,
                     double dragCoeff)

Constructor with drag coefficient min/max set to ±∞.

Parameters:

crossSection - Surface (m²)

dragCoeff - drag coefficient

IsotropicDrag

public IsotropicDrag(double crossSection,
                     double dragCoeff,
                     double dragCoeffMin,
                     double dragCoeffMax)

Constructor with drag coefficient min/max set by user.

Parameters:

crossSection - Surface (m²)

dragCoeff - drag coefficient

dragCoeffMin - Minimum value of drag coefficient

dragCoeffMax - Maximum value of drag coefficient

Method Detail

getDragParametersDrivers

public ParameterDriver[] getDragParametersDrivers()

Get the drivers for supported parameters.

Specified by:

getDragParametersDrivers in interface DragSensitive

Returns:

parameters drivers

dragAcceleration

public Vector3D dragAcceleration(AbsoluteDate date,
                                 Frame frame,
                                 Vector3D position,
                                 Rotation rotation,
                                 double mass,
                                 double density,
                                 Vector3D relativeVelocity,
                                 double[] parameters)

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)

parameters - values of the force model parameters

Returns:

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

dragAcceleration

public <T extends RealFieldElement<T>> FieldVector3D<T> dragAcceleration(FieldAbsoluteDate<T> date,
                                                                         Frame frame,
                                                                         FieldVector3D<T> position,
                                                                         FieldRotation<T> rotation,
                                                                         T mass,
                                                                         T density,
                                                                         FieldVector3D<T> relativeVelocity,
                                                                         T[] parameters)
                                                                  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

Type Parameters:

T - instance of a 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

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)

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

dragAcceleration

public FieldVector3D<DerivativeStructure> dragAcceleration(AbsoluteDate date,
                                                           Frame frame,
                                                           Vector3D position,
                                                           Rotation rotation,
                                                           double mass,
                                                           double density,
                                                           Vector3D relativeVelocity,
                                                           double[] parameters,
                                                           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)

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 derivatives cannot be computed