org.orekit.estimation.iod

Class IodLaplace

java.lang.Object

org.orekit.estimation.iod.IodLaplace

public class IodLaplace
extends Object

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

Laplace algorithm is one of the first method to determine orbits. An orbit is determined from three lines of sight w.r.t. their respective observers inertial positions vectors. For Laplace method, the observer is identical for all observations. Reference: Bate, R., Mueller, D. D., & White, J. E. (1971). Fundamentals of astrodynamics. New York: Dover Publications.

Since:

10.1

Author:

Shiva Iyer

Constructor Summary

Constructors

Constructor and Description
IodLaplace(double mu) Constructor.

Method Summary

Modifier and Type	Method and Description
Orbit	estimate(Frame outputFrame, AngularAzEl azEl1, AngularAzEl azEl2, AngularAzEl azEl3) Estimate the orbit from three angular observations at the same location.
Orbit	estimate(Frame outputFrame, AngularRaDec raDec1, AngularRaDec raDec2, AngularRaDec raDec3) Estimate the orbit from three angular observations at the same location.
Orbit	estimate(Frame outputFrame, PVCoordinates obsPva, AbsoluteDate obsDate1, org.hipparchus.geometry.euclidean.threed.Vector3D los1, AbsoluteDate obsDate2, org.hipparchus.geometry.euclidean.threed.Vector3D los2, AbsoluteDate obsDate3, org.hipparchus.geometry.euclidean.threed.Vector3D los3) Estimate orbit from three line of sight angles at the same location.

Methods inherited from class java.lang.Object

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

Constructor Detail

IodLaplace

public IodLaplace(double mu)

Constructor.

Parameters:

mu - gravitational constant

Method Detail

estimate

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

Estimate the orbit from three angular observations at the same location.

Parameters:

outputFrame - Observer coordinates at time of raDec2

azEl1 - first angular observation

azEl2 - second angular observation

azEl3 - third angular observation

Returns:

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

Since:

12.0

estimate

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

Estimate the orbit from three angular observations at the same location.

Parameters:

outputFrame - Observer coordinates at time of raDec2

raDec1 - first angular observation

raDec2 - second angular observation

raDec3 - third angular observation

Returns:

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

Since:

11.0

estimate

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

Estimate orbit from three line of sight angles at the same location.

Parameters:

outputFrame - inertial frame for observer coordinates and orbit estimate

obsPva - Observer coordinates at time obsDate2

obsDate1 - date of observation 1

los1 - line of sight unit vector 1

obsDate2 - date of observation 2

los2 - line of sight unit vector 2

obsDate3 - date of observation 3

los3 - line of sight unit vector 3

Returns:

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