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, assuming Keplerian motion. An orbit is determined from three angular observations. 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 and Description
IodGooding(double mu) Creator.

Method Summary

Modifier and Type	Method and Description
KeplerianOrbit	estimate(Frame frame, AngularRaDec raDec1, AngularRaDec raDec2, AngularRaDec raDec3, double rho1init, double rho3init) Orbit got from three angular observations.
KeplerianOrbit	estimate(Frame frame, AngularRaDec raDec1, AngularRaDec raDec2, AngularRaDec raDec3, double rho1init, double rho3init, int nRev, boolean direction) Orbit got from three angular observations.
KeplerianOrbit	estimate(Frame frame, Vector3D O1, Vector3D O2, Vector3D O3, Vector3D lineOfSight1, AbsoluteDate dateObs1, Vector3D lineOfSight2, AbsoluteDate dateObs2, Vector3D lineOfSight3, AbsoluteDate dateObs3, double rho1init, double rho3init) Orbit got from Observed Three Lines of Sight (angles only).
KeplerianOrbit	estimate(Frame frame, 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) Orbit got from Observed Three Lines of Sight (angles only).
double	getRange1() Get the range for observation (1).
double	getRange2() Get the range for observation (2).
double	getRange3() Get the range for observation (3).
static Vector3D	lineOfSight(AngularRaDec raDec) Calculate the line of sight vector from an AngularRaDec measurement.
static Vector3D	lineOfSight(double alpha, double delta) Calculates the line of sight vector.

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)

Creator.

Parameters:

mu - gravitational constant

Method Detail

getRange1

public double getRange1()

Get the range for observation (1).

Returns:

the range for observation (1).

getRange2

public double getRange2()

Get the range for observation (2).

Returns:

the range for observation (2).

getRange3

public double getRange3()

Get the range for observation (3).

Returns:

the range for observation (3).

estimate

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

Orbit got from three angular observations.

Parameters:

frame - 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 KeplerianOrbit estimate(Frame frame,
                               AngularRaDec raDec1,
                               AngularRaDec raDec2,
                               AngularRaDec raDec3,
                               double rho1init,
                               double rho3init)

Orbit got from three angular observations.

Parameters:

frame - 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 KeplerianOrbit estimate(Frame frame,
                               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)

Orbit got from Observed Three Lines of Sight (angles only).

Parameters:

frame - 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)

estimate

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

Orbit got from Observed Three Lines of Sight (angles only). assuming there was less than an half revolution between start and final date

Parameters:

frame - 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)

lineOfSight

public static Vector3D lineOfSight(double alpha,
                                   double delta)

Calculates the line of sight vector.

Parameters:

alpha - right ascension angle, in radians

delta - declination angle, in radians

Returns:

the line of sight vector

Since:

11.0

lineOfSight

public static Vector3D lineOfSight(AngularRaDec raDec)

Calculate the line of sight vector from an AngularRaDec measurement.

Parameters:

raDec - measurement

Returns:

the line of sight vector

Since:

11.0