Package org.orekit.propagation

Class OrbitBlender

java.lang.Object

org.orekit.time.AbstractTimeInterpolator<Orbit>

org.orekit.orbits.AbstractOrbitInterpolator

org.orekit.propagation.OrbitBlender

All Implemented Interfaces:

TimeInterpolator<Orbit>

public class OrbitBlender
extends AbstractOrbitInterpolator

Orbit blender.

Its purpose is to interpolate orbit state between tabulated orbit states using the concept of blending, exposed in : "Efficient Covariance Interpolation using Blending of Approximate State Error Transitions" by Sergei Tanygin, and applying it to orbit states instead of covariances.

It propagates tabulated values to the interpolating time using given propagator and then blend each propagated states using a smoothstep function. It gives especially good results as explained here compared to Hermite interpolation when time steps between tabulated values get significant (In LEO, > 10 mn for example).

In most cases, an analytical propagator would be used to quickly fill the gap between tabulated values and recreate a dense ephemeris.

However, a fully configured and accurate numerical propagator can be used to recreate an even more precise ephemeris in case the initial tabulated values were obtained from an external source.

Note that in the current implementation, the returned blended orbit is necessarily Cartesian.

Since:

12.0

Author:

Vincent Cucchietti

See Also:

• SmoothStepFactory
• SmoothStepFactory.SmoothStepFunction
• Propagator
• AbstractAnalyticalPropagator

Nested Class Summary

Nested classes/interfaces inherited from class org.orekit.time.AbstractTimeInterpolator

AbstractTimeInterpolator.InterpolationData

Field Summary

Fields inherited from class org.orekit.time.AbstractTimeInterpolator

DEFAULT_EXTRAPOLATION_THRESHOLD_SEC, DEFAULT_INTERPOLATION_POINTS

Constructor Summary

Constructors

Constructor	Description
OrbitBlender(SmoothStepFactory.SmoothStepFunction blendingFunction, Propagator blendingPropagator, Frame outputInertialFrame)	Default constructor.

Method Summary

Modifier and Type	Method	Description
protected Orbit	interpolate(AbstractTimeInterpolator<Orbit>.InterpolationData interpolationData)	Interpolate instance from given interpolation data.

Methods inherited from class org.orekit.orbits.AbstractOrbitInterpolator

checkOrbitsConsistency, getOutputInertialFrame, interpolate

Methods inherited from class org.orekit.time.AbstractTimeInterpolator

addOptionalSubInterpolatorIfDefined, checkInterpolatorCompatibilityWithSampleSize, getCentralDate, getCentralDate, getExtrapolationThreshold, getInternalNbInterpolationPoints, getNbInterpolationPoints, getSubInterpolators, getTimeParameter, interpolate

Methods inherited from class java.lang.Object

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

Constructor Details

OrbitBlender

public OrbitBlender(SmoothStepFactory.SmoothStepFunction blendingFunction,
 Propagator blendingPropagator,
 Frame outputInertialFrame)

Default constructor.

In most cases, an analytical propagator would be used to quickly fill the gap between tabulated values and recreate a dense ephemeris.

However, a fully configured and accurate numerical propagator can be used to recreate an even more precise ephemeris in case the initial tabulated values were obtained from an external source.

Parameters:

blendingFunction - smoothstep function used for blending

blendingPropagator - propagator used to propagate tabulated orbits to interpolating time

outputInertialFrame - output inertial frame

Throws:

OrekitException - if output frame is not inertial

See Also:

• SmoothStepFactory.SmoothStepFunction

Method Details

interpolate

protected Orbit interpolate(AbstractTimeInterpolator<Orbit>.InterpolationData interpolationData)

Interpolate instance from given interpolation data.

Specified by:

interpolate in class AbstractTimeInterpolator<Orbit>

Parameters:

interpolationData - interpolation data

Returns:

interpolated instance from given interpolation data.