org.orekit.estimation.iod

Class IodGauss

java.lang.Object

org.orekit.estimation.iod.IodGauss

public class IodGauss
extends Object

Gauss angles-only Initial Orbit Determination (IOD) algorithm.

The algorithm works best when the separation between observation is less than about 60°. The method performs remarkably well when the data is separated by 10° or less. An orbit is determined from three lines of sight w.r.t. their respective observers inertial positions vectors.

References: Vallado, D., Fundamentals of Astrodynamics and Applications Curtis, Orbital Mechanics for Engineering Students

Since:

12.0

Author:

Julien Asquier

Constructor Summary

Constructors

Constructor and Description
IodGauss(double mu) Constructor.

Method Summary

Modifier and Type	Method and Description
Orbit	estimate(Frame outputFrame, AngularAzEl azEl1, AngularAzEl azEl2, AngularAzEl azEl3) Estimate and orbit based on Gauss Intial Orbit Determination method.
Orbit	estimate(Frame outputFrame, AngularRaDec raDec1, AngularRaDec raDec2, AngularRaDec raDec3) Estimate and orbit based on Gauss Intial Orbit Determination method.
Orbit	estimate(Frame outputFrame, org.hipparchus.geometry.euclidean.threed.Vector3D obsP1, AbsoluteDate obsDate1, org.hipparchus.geometry.euclidean.threed.Vector3D los1, org.hipparchus.geometry.euclidean.threed.Vector3D obsP2, AbsoluteDate obsDate2, org.hipparchus.geometry.euclidean.threed.Vector3D los2, org.hipparchus.geometry.euclidean.threed.Vector3D obsP3, AbsoluteDate obsDate3, org.hipparchus.geometry.euclidean.threed.Vector3D los3) Estimate and orbit based on Gauss Intial Orbit Determination method.

Methods inherited from class java.lang.Object

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

Constructor Detail

IodGauss

public IodGauss(double mu)

Constructor.

Parameters:

mu - gravitational constant

Method Detail

estimate

public Orbit estimate(Frame outputFrame,
                      AngularAzEl azEl1,
                      AngularAzEl azEl2,
                      AngularAzEl azEl3)

Estimate and orbit based on Gauss Intial Orbit Determination method.

Parameters:

outputFrame - inertial frame for observer coordinates and orbit estimate

azEl1 - first angular observation

azEl2 - second angular observation

azEl3 - third angular observation

Returns:

an estimate of the orbit at the central date or null if no estimate is possible with the given data

estimate

public Orbit estimate(Frame outputFrame,
                      AngularRaDec raDec1,
                      AngularRaDec raDec2,
                      AngularRaDec raDec3)

Estimate and orbit based on Gauss Intial Orbit Determination method.

Parameters:

outputFrame - inertial frame for observer coordinates and orbit estimate

raDec1 - first angular observation

raDec2 - second angular observation

raDec3 - third angular observation

Returns:

an estimate of the orbit at the central date or null if no estimate is possible with the given data

estimate

public Orbit estimate(Frame outputFrame,
                      org.hipparchus.geometry.euclidean.threed.Vector3D obsP1,
                      AbsoluteDate obsDate1,
                      org.hipparchus.geometry.euclidean.threed.Vector3D los1,
                      org.hipparchus.geometry.euclidean.threed.Vector3D obsP2,
                      AbsoluteDate obsDate2,
                      org.hipparchus.geometry.euclidean.threed.Vector3D los2,
                      org.hipparchus.geometry.euclidean.threed.Vector3D obsP3,
                      AbsoluteDate obsDate3,
                      org.hipparchus.geometry.euclidean.threed.Vector3D los3)

Estimate and orbit based on Gauss Intial Orbit Determination method.

Parameters:

outputFrame - inertial frame for observer coordinates and orbit estimate

obsP1 - observer position at obsDate1

obsDate1 - date of the 1st observation

los1 - line of sight unit vector at obsDate1

obsP2 - observer position at obsDate2

obsDate2 - date of the 2nd observation

los2 - line of sight unit vector at obsDate2

obsP3 - observer position at obsDate3

obsDate3 - date of the 3rd observation

los3 - line of sight unit vector at obsDate3

Returns:

an estimate of the orbit at the central date obsDate2 or null if no estimate is possible with the given data