org.orekit.tutorials.estimation

Class TLEBasedOrbitDetermination

java.lang.Object

org.orekit.tutorials.estimation.common.AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

org.orekit.tutorials.estimation.TLEBasedOrbitDetermination

public class TLEBasedOrbitDetermination
extends AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

The purpose of the tutorial is to present a TLE based orbit determination.

Position data from a SP3 file are used as observations for the orbit determination process. The dynamical model used for the satellite is the SGP4/SDP4 model. An input TLE (from Celestrak) is used as initial guess. The purpose is to generate a new TLE, with a better accuracy thanks to the estimation process.

Author:

Bryan Cazabonne

Constructor Summary

Constructors

Constructor and Description
TLEBasedOrbitDetermination()

Method Summary

Modifier and Type	Method and Description
protected void	compareWithReference(org.orekit.orbits.Orbit estimatedOrbit) Compare the estimated orbit with a reference orbit.
protected void	createGravityField(TutorialOrbitDetermination inputData) Create a gravity field from input parameters.
protected org.orekit.propagation.conversion.TLEPropagatorBuilder	createPropagatorBuilder(org.orekit.orbits.Orbit referenceOrbit, org.orekit.propagation.conversion.ODEIntegratorBuilder builder, double positionScale) Create a propagator builder from input parameters.
protected void	finish(org.orekit.propagation.Propagator[] estimated) Initialization just after orekit-data setting.
protected double	getMu() Get the central attraction coefficient.
protected void	init(TutorialOrbitDetermination inputData) Initialization just after orekit-data setting.
static void	main(String[] args) Program entry point.
protected void	setAttitudeProvider(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder, org.orekit.attitudes.AttitudeProvider attitudeProvider) Set attitude provider.
protected List<org.orekit.utils.ParameterDriver>	setDrag(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder, org.orekit.models.earth.atmosphere.Atmosphere atmosphere, org.orekit.forces.drag.DragSensitive spacecraft) Set drag force model.
protected List<org.orekit.utils.ParameterDriver>	setGravity(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder, org.orekit.bodies.OneAxisEllipsoid body) Set gravity force model.
protected List<org.orekit.utils.ParameterDriver>	setManeuver(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder, org.orekit.time.AbsoluteDate fireDate, double duration, double thrust, double isp, org.hipparchus.geometry.euclidean.threed.Vector3D direction, String name) Set maneuver model.
protected void	setMass(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder, double mass) Set satellite mass.
protected List<org.orekit.utils.ParameterDriver>	setOceanTides(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder, org.orekit.utils.IERSConventions conventions, org.orekit.bodies.OneAxisEllipsoid body, int degree, int order) Set third body attraction force model.
protected List<org.orekit.utils.ParameterDriver>	setPolynomialAcceleration(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder, String name, org.hipparchus.geometry.euclidean.threed.Vector3D direction, int degree) Set polynomial acceleration force model.
protected List<org.orekit.utils.ParameterDriver>	setRelativity(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder) Set relativity force model.
protected List<org.orekit.utils.ParameterDriver>	setSolarRadiationPressure(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder, org.orekit.bodies.CelestialBody sun, org.orekit.bodies.OneAxisEllipsoid earth, org.orekit.forces.radiation.RadiationSensitive spacecraft) Set solar radiation pressure force model.
protected List<org.orekit.utils.ParameterDriver>	setSolidTides(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder, org.orekit.utils.IERSConventions conventions, org.orekit.bodies.OneAxisEllipsoid body, org.orekit.bodies.CelestialBody[] solidTidesBodies) Set third body attraction force model.
protected List<org.orekit.utils.ParameterDriver>	setThirdBody(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder, org.orekit.bodies.CelestialBody thirdBody) Set third body attraction force model.

Methods inherited from class org.orekit.tutorials.estimation.common.AbstractOrbitDetermination

run, runKalman, runReference

Methods inherited from class java.lang.Object

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

Constructor Detail

TLEBasedOrbitDetermination

public TLEBasedOrbitDetermination()

Method Detail

main

public static void main(String[] args)

Program entry point.

Parameters:

args - program arguments (unused here)

init

protected void init(TutorialOrbitDetermination inputData)

Initialization just after orekit-data setting.

By default, does nothing.

Overrides:

init in class AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

Parameters:

inputData - input data

finish

protected void finish(org.orekit.propagation.Propagator[] estimated)

Initialization just after orekit-data setting.

By default, does nothing.

Overrides:

finish in class AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

Parameters:

estimated - estimated propagators

createGravityField

protected void createGravityField(TutorialOrbitDetermination inputData)
                           throws NoSuchElementException

Create a gravity field from input parameters.

Specified by:

createGravityField in class AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

Parameters:

inputData - input data

Throws:

NoSuchElementException - if input parameters are missing

getMu

protected double getMu()

Get the central attraction coefficient.

Specified by:

getMu in class AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

Returns:

central attraction coefficient

createPropagatorBuilder

protected org.orekit.propagation.conversion.TLEPropagatorBuilder createPropagatorBuilder(org.orekit.orbits.Orbit referenceOrbit,
                                                                                         org.orekit.propagation.conversion.ODEIntegratorBuilder builder,
                                                                                         double positionScale)

Create a propagator builder from input parameters.

The advantage of using the DSST instead of the numerical propagator is that it is possible to use greater values for the minimum and maximum integration steps.

Specified by:

createPropagatorBuilder in class AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

Parameters:

referenceOrbit - reference orbit from which real orbits will be built

builder - first order integrator builder

positionScale - scaling factor used for orbital parameters normalization (typically set to the expected standard deviation of the position)

Returns:

propagator builder

setMass

protected void setMass(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder,
                       double mass)

Set satellite mass.

Specified by:

setMass in class AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

Parameters:

propagatorBuilder - propagator builder

mass - initial mass

setGravity

protected List<org.orekit.utils.ParameterDriver> setGravity(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder,
                                                            org.orekit.bodies.OneAxisEllipsoid body)

Set gravity force model.

Specified by:

setGravity in class AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

Parameters:

propagatorBuilder - propagator builder

body - central body

Returns:

drivers for the force model

setOceanTides

protected List<org.orekit.utils.ParameterDriver> setOceanTides(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder,
                                                               org.orekit.utils.IERSConventions conventions,
                                                               org.orekit.bodies.OneAxisEllipsoid body,
                                                               int degree,
                                                               int order)

Set third body attraction force model.

Specified by:

setOceanTides in class AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

Parameters:

propagatorBuilder - propagator builder

conventions - IERS conventions to use

body - central body

degree - degree of the tide model to load

order - order of the tide model to load

Returns:

drivers for the force model

setSolidTides

protected List<org.orekit.utils.ParameterDriver> setSolidTides(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder,
                                                               org.orekit.utils.IERSConventions conventions,
                                                               org.orekit.bodies.OneAxisEllipsoid body,
                                                               org.orekit.bodies.CelestialBody[] solidTidesBodies)

Set third body attraction force model.

Specified by:

setSolidTides in class AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

Parameters:

propagatorBuilder - propagator builder

conventions - IERS conventions to use

body - central body

solidTidesBodies - third bodies generating solid tides

Returns:

drivers for the force model

setThirdBody

protected List<org.orekit.utils.ParameterDriver> setThirdBody(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder,
                                                              org.orekit.bodies.CelestialBody thirdBody)

Set third body attraction force model.

Specified by:

setThirdBody in class AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

Parameters:

propagatorBuilder - propagator builder

thirdBody - third body

Returns:

drivers for the force model

setDrag

protected List<org.orekit.utils.ParameterDriver> setDrag(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder,
                                                         org.orekit.models.earth.atmosphere.Atmosphere atmosphere,
                                                         org.orekit.forces.drag.DragSensitive spacecraft)

Set drag force model.

Specified by:

setDrag in class AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

Parameters:

propagatorBuilder - propagator builder

atmosphere - atmospheric model

spacecraft - spacecraft model

Returns:

drivers for the force model

setSolarRadiationPressure

protected List<org.orekit.utils.ParameterDriver> setSolarRadiationPressure(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder,
                                                                           org.orekit.bodies.CelestialBody sun,
                                                                           org.orekit.bodies.OneAxisEllipsoid earth,
                                                                           org.orekit.forces.radiation.RadiationSensitive spacecraft)

Set solar radiation pressure force model.

Specified by:

setSolarRadiationPressure in class AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

Parameters:

propagatorBuilder - propagator builder

sun - Sun model

earth - Earth body shape

spacecraft - spacecraft model

Returns:

drivers for the force model

setRelativity

protected List<org.orekit.utils.ParameterDriver> setRelativity(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder)

Set relativity force model.

Specified by:

setRelativity in class AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

Parameters:

propagatorBuilder - propagator builder

Returns:

drivers for the force model

setPolynomialAcceleration

protected List<org.orekit.utils.ParameterDriver> setPolynomialAcceleration(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder,
                                                                           String name,
                                                                           org.hipparchus.geometry.euclidean.threed.Vector3D direction,
                                                                           int degree)

Set polynomial acceleration force model.

Specified by:

setPolynomialAcceleration in class AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

Parameters:

propagatorBuilder - propagator builder

name - name of the acceleration

direction - normalized direction of the acceleration

degree - polynomial degree

Returns:

drivers for the force model

setAttitudeProvider

protected void setAttitudeProvider(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder,
                                   org.orekit.attitudes.AttitudeProvider attitudeProvider)

Set attitude provider.

Specified by:

setAttitudeProvider in class AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

Parameters:

propagatorBuilder - propagator builder

attitudeProvider - attitude provider

compareWithReference

protected void compareWithReference(org.orekit.orbits.Orbit estimatedOrbit)
                             throws IOException

Compare the estimated orbit with a reference orbit.

Specified by:

compareWithReference in class AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

Parameters:

estimatedOrbit - estimated orbit

Throws:

IOException - Input file cannot be opened

setManeuver

protected List<org.orekit.utils.ParameterDriver> setManeuver(org.orekit.propagation.conversion.TLEPropagatorBuilder propagatorBuilder,
                                                             org.orekit.time.AbsoluteDate fireDate,
                                                             double duration,
                                                             double thrust,
                                                             double isp,
                                                             org.hipparchus.geometry.euclidean.threed.Vector3D direction,
                                                             String name)

Description copied from class: AbstractOrbitDetermination

Set maneuver model.

Specified by:

setManeuver in class AbstractOrbitDetermination<org.orekit.propagation.conversion.TLEPropagatorBuilder>

Parameters:

propagatorBuilder - propagator builder

fireDate - maneuver date

duration - the duration of the thrust (s) (if negative, the date is considered to be the stop date)

thrust - the thrust force (N)

isp - engine specific impulse (s)

direction - the acceleration direction in satellite frame.

name - of the maneuver

Returns:

drivers for the force mode