Package org.orekit.estimation.iod

Class IodHerrickGibbs

java.lang.Object

org.orekit.estimation.iod.IodHerrickGibbs

public class IodHerrickGibbs
extends Object

HerrickGibbs position-based Initial Orbit Determination (IOD) algorithm.

An orbit is determined from three position vectors. Because Gibbs IOD algorithm is limited when the position vectors are to close to one other, Herrick-Gibbs IOD algorithm is a variation made to address this limitation. Because this method is only approximate, it is not robust as the Gibbs method for other cases.

Since:

13.1

Author:

Bryan Cazabonne

See Also:

• "Vallado, D., Fundamentals of Astrodynamics and Applications, 4th Edition."

Constructor Summary

Constructors

Constructor	Description
IodHerrickGibbs(double mu)	Constructor.

Method Summary

Modifier and Type	Method	Description
<T extends CalculusFieldElement<T>> FieldOrbit<T>	estimate(Frame frame, FieldVector3D<T> r1, FieldAbsoluteDate<T> date1, FieldVector3D<T> r2, FieldAbsoluteDate<T> date2, FieldVector3D<T> r3, FieldAbsoluteDate<T> date3)	Give an initial orbit estimation, assuming Keplerian motion.
Orbit	estimate(Frame frame, Vector3D r1, AbsoluteDate date1, Vector3D r2, AbsoluteDate date2, Vector3D r3, AbsoluteDate date3)	Give an initial orbit estimation, assuming Keplerian motion.
Orbit	estimate(Frame frame, Position p1, Position p2, Position p3)	Give an initial orbit estimation, assuming Keplerian motion.
Orbit	estimate(Frame frame, PV pv1, PV pv2, PV pv3)	Give an initial orbit estimation, assuming Keplerian motion.

Methods inherited from class java.lang.Object

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

Constructor Details

IodHerrickGibbs

public IodHerrickGibbs(double mu)

Constructor.

Parameters:

mu - gravitational constant

Method Details

estimate

public Orbit estimate(Frame frame,
 Position p1,
 Position p2,
 Position p3)

Give an initial orbit estimation, assuming Keplerian motion.

All observations should be from the same location.

Parameters:

frame - measurements frame, used as output orbit frame

p1 - First position measurement

p2 - Second position measurement

p3 - Third position measurement

Returns:

an initial orbit estimation at the central date (i.e., date of the second position measurement)

estimate

public Orbit estimate(Frame frame,
 PV pv1,
 PV pv2,
 PV pv3)

Give an initial orbit estimation, assuming Keplerian motion.

All observations should be from the same location.

Parameters:

frame - measurements frame, used as output orbit frame

pv1 - First PV measurement

pv2 - Second PV measurement

pv3 - Third PV measurement

Returns:

an initial orbit estimation at the central date (i.e., date of the second PV measurement)

estimate

public Orbit estimate(Frame frame,
 Vector3D r1,
 AbsoluteDate date1,
 Vector3D r2,
 AbsoluteDate date2,
 Vector3D r3,
 AbsoluteDate date3)

Give an initial orbit estimation, assuming Keplerian motion.

All observations should be from the same location.

Parameters:

frame - measurements frame, used as output orbit frame

r1 - position vector 1, expressed in frame

date1 - epoch of position vector 1

r2 - position vector 2, expressed in frame

date2 - epoch of position vector 2

r3 - position vector 3, expressed in frame

date3 - epoch of position vector 3

Returns:

an initial orbit estimation at the central date (i.e., date of the second position measurement)

estimate

public <T extends CalculusFieldElement<T>>
FieldOrbit<T> estimate(Frame frame,
 FieldVector3D<T> r1,
 FieldAbsoluteDate<T> date1,
 FieldVector3D<T> r2,
 FieldAbsoluteDate<T> date2,
 FieldVector3D<T> r3,
 FieldAbsoluteDate<T> date3)

Give an initial orbit estimation, assuming Keplerian motion.

All observations should be from the same location.

Type Parameters:

T - type of the elements

Parameters:

frame - measurements frame, used as output orbit frame

r1 - position vector 1, expressed in frame

date1 - epoch of position vector 1

r2 - position vector 2, expressed in frame

date2 - epoch of position vector 2

r3 - position vector 3, expressed in frame

date3 - epoch of position vector 3

Returns:

an initial orbit estimation at the central date (i.e., date of the second position measurement)