Package org.orekit.estimation.iod

Class IodGooding

java.lang.Object

org.orekit.estimation.iod.IodGooding

public class IodGooding
extends Object

Gooding angles only Initial Orbit Determination (IOD) algorithm, assuming Keplerian motion.

An orbit is determined from three lines of sight w.r.t. their respective observers inertial positions vectors. Gooding algorithm can handle multiple satellite's revolutions. Reference: Gooding, R.H., A New Procedure for Orbit Determination Based on Three Lines of Sight (Angles only), Technical Report 93004, April 1993

Since:

8.0

Author:

Joris Olympio

Constructor Summary

Constructors

Constructor	Description
IodGooding(double mu)	Constructor.

Method Summary

Modifier and Type	Method	Description
Orbit	estimate(Frame outputFrame, Vector3D O1, Vector3D O2, Vector3D O3, Vector3D lineOfSight1, AbsoluteDate dateObs1, Vector3D lineOfSight2, AbsoluteDate dateObs2, Vector3D lineOfSight3, AbsoluteDate dateObs3, double rho1init, double rho3init)	Estimate orbit from three line of sight.
Orbit	estimate(Frame outputFrame, Vector3D O1, Vector3D O2, Vector3D O3, Vector3D lineOfSight1, AbsoluteDate dateObs1, Vector3D lineOfSight2, AbsoluteDate dateObs2, Vector3D lineOfSight3, AbsoluteDate dateObs3, double rho1init, double rho3init, int nRev, boolean direction)	Estimate orbit from three line of sight.
Orbit	estimate(Frame outputFrame, AngularAzEl azEl1, AngularAzEl azEl2, AngularAzEl azEl3, double rho1init, double rho3init)	Estimate orbit from three angular observations.
Orbit	estimate(Frame outputFrame, AngularAzEl azEl1, AngularAzEl azEl2, AngularAzEl azEl3, double rho1init, double rho3init, int nRev, boolean direction)	Estimate orbit from three angular observations.
Orbit	estimate(Frame outputFrame, AngularRaDec raDec1, AngularRaDec raDec2, AngularRaDec raDec3, double rho1init, double rho3init)	Estimate orbit from three angular observations.
Orbit	estimate(Frame outputFrame, AngularRaDec raDec1, AngularRaDec raDec2, AngularRaDec raDec3, double rho1init, double rho3init, int nRev, boolean direction)	Estimate orbit from three angular observations.
double	getRange1()	Get range for observation (1).
double	getRange2()	Get range for observation (2).
double	getRange3()	Get range for observation (3).

Methods inherited from class java.lang.Object

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

Constructor Detail

IodGooding

public IodGooding(double mu)

Constructor.

Parameters:

mu - gravitational constant

Method Detail

getRange1

public double getRange1()

Get range for observation (1).

Returns:

the range for observation (1)

getRange2

public double getRange2()

Get range for observation (2).

Returns:

the range for observation (2)

getRange3

public double getRange3()

Get range for observation (3).

Returns:

the range for observation (3)

estimate

public Orbit estimate(Frame outputFrame,
                      AngularAzEl azEl1,
                      AngularAzEl azEl2,
                      AngularAzEl azEl3,
                      double rho1init,
                      double rho3init)

Estimate orbit from three angular observations.

This signature assumes there was less than an half revolution between start and final date

Parameters:

outputFrame - inertial frame for observer coordinates and orbit estimate

azEl1 - first angular observation

azEl2 - second angular observation

azEl3 - third angular observation

rho1init - initial guess of the range problem. range 1, in meters

rho3init - initial guess of the range problem. range 3, in meters

Returns:

an estimate of the Keplerian orbit at the central date (i.e., date of the second angular observation)

Since:

12.0

estimate

public Orbit estimate(Frame outputFrame,
                      AngularAzEl azEl1,
                      AngularAzEl azEl2,
                      AngularAzEl azEl3,
                      double rho1init,
                      double rho3init,
                      int nRev,
                      boolean direction)

Estimate orbit from three angular observations.

Parameters:

outputFrame - inertial frame for observer coordinates and orbit estimate

azEl1 - first angular observation

azEl2 - second angular observation

azEl3 - third angular observation

rho1init - initial guess of the range problem. range 1, in meters

rho3init - initial guess of the range problem. range 3, in meters

nRev - number of complete revolutions between observation 1 and 3

direction - true if posigrade (short way)

Returns:

an estimate of the Keplerian orbit at the central date (i.e., date of the second angular observation)

Since:

11.0

estimate

public Orbit estimate(Frame outputFrame,
                      AngularRaDec raDec1,
                      AngularRaDec raDec2,
                      AngularRaDec raDec3,
                      double rho1init,
                      double rho3init)

Estimate orbit from three angular observations.

This signature assumes there was less than an half revolution between start and final date

Parameters:

outputFrame - inertial frame for observer coordinates and orbit estimate

raDec1 - first angular observation

raDec2 - second angular observation

raDec3 - third angular observation

rho1init - initial guess of the range problem. range 1, in meters

rho3init - initial guess of the range problem. range 3, in meters

Returns:

an estimate of the Keplerian orbit at the central date (i.e., date of the second angular observation)

Since:

11.0

estimate

public Orbit estimate(Frame outputFrame,
                      AngularRaDec raDec1,
                      AngularRaDec raDec2,
                      AngularRaDec raDec3,
                      double rho1init,
                      double rho3init,
                      int nRev,
                      boolean direction)

Estimate orbit from three angular observations.

Parameters:

outputFrame - inertial frame for observer coordinates and orbit estimate

raDec1 - first angular observation

raDec2 - second angular observation

raDec3 - third angular observation

rho1init - initial guess of the range problem. range 1, in meters

rho3init - initial guess of the range problem. range 3, in meters

nRev - number of complete revolutions between observation 1 and 3

direction - true if posigrade (short way)

Returns:

an estimate of the Keplerian orbit at the central date (i.e., date of the second angular observation)

Since:

11.0

estimate

public Orbit estimate(Frame outputFrame,
                      Vector3D O1,
                      Vector3D O2,
                      Vector3D O3,
                      Vector3D lineOfSight1,
                      AbsoluteDate dateObs1,
                      Vector3D lineOfSight2,
                      AbsoluteDate dateObs2,
                      Vector3D lineOfSight3,
                      AbsoluteDate dateObs3,
                      double rho1init,
                      double rho3init)

Estimate orbit from three line of sight.

This signature assumes there was less than an half revolution between start and final date

Parameters:

outputFrame - inertial frame for observer coordinates and orbit estimate

O1 - Observer position 1

O2 - Observer position 2

O3 - Observer position 3

lineOfSight1 - line of sight 1

dateObs1 - date of observation 1

lineOfSight2 - line of sight 2

dateObs2 - date of observation 1

lineOfSight3 - line of sight 3

dateObs3 - date of observation 1

rho1init - initial guess of the range problem. range 1, in meters

rho3init - initial guess of the range problem. range 3, in meters

Returns:

an estimate of the Keplerian orbit at the central date (i.e., date of the second angular observation)

estimate

public Orbit estimate(Frame outputFrame,
                      Vector3D O1,
                      Vector3D O2,
                      Vector3D O3,
                      Vector3D lineOfSight1,
                      AbsoluteDate dateObs1,
                      Vector3D lineOfSight2,
                      AbsoluteDate dateObs2,
                      Vector3D lineOfSight3,
                      AbsoluteDate dateObs3,
                      double rho1init,
                      double rho3init,
                      int nRev,
                      boolean direction)

Estimate orbit from three line of sight.

Parameters:

outputFrame - inertial frame for observer coordinates and orbit estimate

O1 - Observer position 1

O2 - Observer position 2

O3 - Observer position 3

lineOfSight1 - line of sight 1

dateObs1 - date of observation 1

lineOfSight2 - line of sight 2

dateObs2 - date of observation 2

lineOfSight3 - line of sight 3

dateObs3 - date of observation 3

rho1init - initial guess of the range problem. range 1, in meters

rho3init - initial guess of the range problem. range 3, in meters

nRev - number of complete revolutions between observation1 and 3

direction - true if posigrade (short way)

Returns:

an estimate of the Keplerian orbit at the central date (i.e., date of the second angular observation)