fr.cnes.sirius.patrius.assembly.models
Class GlobalDragCoefficientProvider

java.lang.Object
  fr.cnes.sirius.patrius.assembly.models.GlobalDragCoefficientProvider

All Implemented Interfaces:

DragCoefficientProvider

public class GlobalDragCoefficientProvider
extends Object
implements DragCoefficientProvider

Implementation of DragCoefficientProvider computing aero coefficients as functions of type TrivariateFunction. The service #getCoefficients(Vector3D, AtmosphereData, Assembly) is implemented using these functions in which a 3D interpolation (linear or by spline) is performed. The considered interpolation point has (azimuth, elevation, s) coordinates, s being the velocity factor, such that :

• the azimuth is the angle between X satellite axis and the projection of the relative velocity in satellite plane (XY).
• the elevation is the angle between the relative velocity and its projection in satellite plane (XY), in the satellite's frame.
• s is computed knowing :

   s2  = || V_rel ||2 / 2r T_atmos 

This model uses 3 parameters (azimuth, elevation, s factor) to compute 12 output being the aero coefficients :

SC_abs (x, y, z): absorption coefficients

SC_spec (x, y, z): specular coefficients

SC_diff_av (x, y, z): diffuse coefficients (front face)

SC_diff_ar (x, y, z): diffuse coefficients (rear face)

Since:

3.4

Version:

$Id: GlobalDragCoefficientProvider.java 17627 2017-05-22 07:15:27Z bignon $

Author:

rodriguest

See Also:

InterpolatedDragReader

Concurrency :

thread-safe

Nested Class Summary

static class

GlobalDragCoefficientProvider.INTERP Enumerate to choose the way to interpolate.

Constructor Summary

GlobalDragCoefficientProvider(GlobalDragCoefficientProvider.INTERP method, String filePath)
Constructor.

Method Summary

DragCoefficient

getCoefficients(Vector3D relativeVelocity, AtmosphereData atmoData, Assembly assembly) Provides drag coefficient (x surface).

Methods inherited from class java.lang.Object

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

Constructor Detail

GlobalDragCoefficientProvider

public GlobalDragCoefficientProvider(GlobalDragCoefficientProvider.INTERP method,
                                     String filePath)
                              throws IOException,
                                     OrekitException

Constructor.

Parameters:

method - the method chosen for interpolation : could be linear or by splines

filePath - absolute path to the file containing the aero coefficients

Throws:

IOException - if file could not be read.

OrekitException - thrown if number of input + output in file is not 15 or some lines are missing

Method Detail

getCoefficients

public DragCoefficient getCoefficients(Vector3D relativeVelocity,
                                       AtmosphereData atmoData,
                                       Assembly assembly)

Description copied from interface: DragCoefficientProvider

Provides drag coefficient (x surface).

Specified by:

getCoefficients in interface DragCoefficientProvider

Parameters:

relativeVelocity - relative velocity of atmosphere with respect to spacecraft in satellite frame

atmoData - atmosphere data

assembly - assembly

Returns:

drag coefficient (x surface) in satellite frame