Package org.orekit.propagation.analytical.tle

Class DeepSDP4

java.lang.Object

org.orekit.propagation.AbstractPropagator

org.orekit.propagation.analytical.AbstractAnalyticalPropagator

org.orekit.propagation.analytical.tle.TLEPropagator

org.orekit.propagation.analytical.tle.DeepSDP4

All Implemented Interfaces:

Propagator, PVCoordinatesProvider

public class DeepSDP4
extends TLEPropagator

This class contains the methods that compute deep space perturbation terms.

The user should not bother in this class since it is handled internaly by the TLEPropagator.

This implementation is largely inspired from the paper and source code Revisiting Spacetrack Report #3 and is fully compliant with its results and tests cases.

Author:

Felix R. Hoots, Ronald L. Roehrich, December 1980 (original fortran), David A. Vallado, Paul Crawford, Richard Hujsak, T.S. Kelso (C++ translation and improvements), Fabien Maussion (java translation)

Field Summary

Fields

Modifier and Type	Field	Description
protected double	em	New eccentricity.
protected double	omgadf	New perigee argument.
protected double	xinc	New inclination.
protected double	xll	Parameter for xl computation.
protected double	xn	New mean motion.

Fields inherited from interface org.orekit.propagation.Propagator

DEFAULT_LAW, DEFAULT_MASS, EPHEMERIS_GENERATION_MODE, MASTER_MODE, SLAVE_MODE

Fields inherited from class org.orekit.propagation.analytical.tle.TLEPropagator

a, a0dp, beta0, beta02, c1, c2, c4, coef, coef1, cosi0, e, e0sq, eeta, eta, etasq, i, omega, omgdot, perige, s4, sini0, t2cof, theta2, tle, tsi, xl, xmdot, xn0dp, xnodcf, xnode, xnodot

Constructor Summary

Constructors

Constructor	Description
DeepSDP4(TLE initialTLE, AttitudeProvider attitudeProvider, double mass)	Constructor for a unique initial TLE.

Method Summary

Modifier and Type	Method	Description
protected void	deepPeriodicEffects(double t)	Computes periodic terms from current coordinates and epoch.
protected void	deepSecularEffects(double t)	Computes secular terms from current coordinates and epoch.
protected void	luniSolarTermsComputation()	Computes luni - solar terms from initial coordinates and epoch.
protected void	sxpInitialize()	Initialization proper to each propagator (SGP or SDP).
protected void	sxpPropagate(double tSince)	Propagation proper to each propagator (SGP or SDP).
protected static double	thetaG(AbsoluteDate date)	Computes SPACETRACK#3 compliant earth rotation angle.

Methods inherited from class org.orekit.propagation.analytical.AbstractAnalyticalPropagator

acceptStep, addEventDetector, basicPropagate, clearEventsDetectors, getEventsDetectors, getGeneratedEphemeris, getPvProvider, propagate

Methods inherited from class org.orekit.propagation.AbstractPropagator

addAdditionalStateProvider, getAdditionalStateProviders, getAttitudeProvider, getFixedStepSize, getInitialState, getManagedAdditionalStates, getMode, getPVCoordinates, getStartDate, getStepHandler, isAdditionalStateManaged, propagate, setAttitudeProvider, setEphemerisMode, setEphemerisMode, setMasterMode, setMasterMode, setSlaveMode, setStartDate, updateAdditionalStates

Methods inherited from class java.lang.Object

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

Methods inherited from class org.orekit.propagation.analytical.tle.TLEPropagator

getFrame, getMass, getMU, getPVCoordinates, getTLE, propagateOrbit, resetInitialState, resetIntermediateState, selectExtrapolator, selectExtrapolator

Field Detail

omgadf

protected double omgadf

New perigee argument.

xn

protected double xn

New mean motion.

xll

protected double xll

Parameter for xl computation.

em

protected double em

New eccentricity.

xinc

protected double xinc

New inclination.

Constructor Detail

DeepSDP4

public DeepSDP4(TLE initialTLE,
                AttitudeProvider attitudeProvider,
                double mass)
         throws OrekitException

Constructor for a unique initial TLE.

Parameters:

initialTLE - the TLE to propagate.

attitudeProvider - provider for attitude computation

mass - spacecraft mass (kg)

Throws:

OrekitException - if some specific error occurs

Method Detail

luniSolarTermsComputation

protected void luniSolarTermsComputation()
                                  throws OrekitException

Computes luni - solar terms from initial coordinates and epoch.

Throws:

OrekitException - when UTC time steps can't be read

deepSecularEffects

protected void deepSecularEffects(double t)

Computes secular terms from current coordinates and epoch.

Parameters:

t - offset from initial epoch (minutes)

deepPeriodicEffects

protected void deepPeriodicEffects(double t)

Computes periodic terms from current coordinates and epoch.

Parameters:

t - offset from initial epoch (min)

sxpInitialize

protected void sxpInitialize()
                      throws OrekitException

Initialization proper to each propagator (SGP or SDP).

Specified by:

sxpInitialize in class TLEPropagator

Throws:

OrekitException - when UTC time steps can't be read

sxpPropagate

protected void sxpPropagate(double tSince)

Propagation proper to each propagator (SGP or SDP).

Specified by:

sxpPropagate in class TLEPropagator

Parameters:

tSince - the offset from initial epoch (minutes)

thetaG

protected static double thetaG(AbsoluteDate date)
                        throws OrekitException

Computes SPACETRACK#3 compliant earth rotation angle.

Parameters:

date - the current date

Returns:

the ERA (rad)

Throws:

OrekitException - when UTC time steps can't be read