org.orekit.propagation.semianalytical.dsst.forces

Class DSSTAtmosphericDrag

java.lang.Object

org.orekit.propagation.semianalytical.dsst.forces.AbstractGaussianContribution

org.orekit.propagation.semianalytical.dsst.forces.DSSTAtmosphericDrag

All Implemented Interfaces:

DSSTForceModel

public class DSSTAtmosphericDrag
extends AbstractGaussianContribution

Atmospheric drag contribution to the DSSTPropagator.

The drag acceleration is computed as follows:
γ = (1/2 ρ C_D A_Ref / m) * |v_atm - v_sat| * (v_atm - v_sat)

Author:

Pascal Parraud

Field Summary

Fields inherited from class org.orekit.propagation.semianalytical.dsst.forces.AbstractGaussianContribution

a, A, B, C, co2AB, ecc, f, g, h, I, k, n, ooA, ooAB, ooBpo, ooMu, p, q, ton2a, w

Constructor Summary

Constructors

Constructor and Description
DSSTAtmosphericDrag(Atmosphere atmosphere, double cd, double area) Simple constructor.

Method Summary

Methods

Modifier and Type	Method and Description
protected Vector3D	getAcceleration(SpacecraftState state, Vector3D position, Vector3D velocity) Compute the acceleration due to the non conservative perturbing force.
double	getArea() Get the cross sectional area of satellite.
Atmosphere	getAtmosphere() Get the atmospheric model.
double	getCd() Get the drag coefficient.
EventDetector[]	getEventsDetectors() Get the discrete events related to the model.
protected double[]	getLLimits(SpacecraftState state) Compute the limits in L, the true longitude, for integration.
double	getRbar() Get the critical distance.
double[]	getShortPeriodicVariations(AbsoluteDate date, double[] meanElements) Computes the short periodic variations.

Methods inherited from class org.orekit.propagation.semianalytical.dsst.forces.AbstractGaussianContribution

getMeanElementRate, initialize, initializeStep

Methods inherited from class java.lang.Object

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

Constructor Detail

DSSTAtmosphericDrag

public DSSTAtmosphericDrag(Atmosphere atmosphere,
                   double cd,
                   double area)

Simple constructor.

Parameters:

atmosphere - atmospheric model

cd - drag coefficient

area - cross sectionnal area of satellite

Method Detail

getAtmosphere

public Atmosphere getAtmosphere()

Get the atmospheric model.

Returns:

atmosphere model

getArea

public double getArea()

Get the cross sectional area of satellite.

Returns:

cross sectional area (m²)

getCd

public double getCd()

Get the drag coefficient.

Returns:

drag coefficient

getRbar

public double getRbar()

Get the critical distance.

The critical distance from the center of the central body aims at defining the atmosphere entry/exit.

Returns:

the critical distance from the center of the central body (m)

getShortPeriodicVariations

public double[] getShortPeriodicVariations(AbsoluteDate date,
                                  double[] meanElements)
                                    throws OrekitException

Computes the short periodic variations.

Parameters:

date - current date

meanElements - mean elements at current date

Returns:

the short periodic variations

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

getAcceleration

protected Vector3D getAcceleration(SpacecraftState state,
                       Vector3D position,
                       Vector3D velocity)
                            throws OrekitException

Compute the acceleration due to the non conservative perturbing force.

Specified by:

getAcceleration in class AbstractGaussianContribution

Parameters:

state - current state information: date, kinematics, attitude

position - spacecraft position

velocity - spacecraft velocity

Returns:

the perturbing acceleration

Throws:

OrekitException - if some specific error occurs

getLLimits

protected double[] getLLimits(SpacecraftState state)
                       throws OrekitException

Compute the limits in L, the true longitude, for integration.

Specified by:

getLLimits in class AbstractGaussianContribution

Parameters:

state - current state information: date, kinematics, attitude

Returns:

the integration limits in L

Throws:

OrekitException - if some specific error occurs