Package org.orekit.propagation.analytical.tle

Class SGP4

java.lang.Object

org.orekit.propagation.AbstractPropagator

org.orekit.propagation.analytical.AbstractAnalyticalPropagator

org.orekit.propagation.analytical.tle.TLEPropagator

org.orekit.propagation.analytical.tle.SGP4

All Implemented Interfaces:

Propagator, PVCoordinatesProvider

public class SGP4
extends TLEPropagator

This class contains methods to compute propagated coordinates with the SGP4 model.

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 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
SGP4(TLE initialTLE, AttitudeProvider attitudeProvider, double mass)	Constructor for a unique initial TLE.

Method Summary

Modifier and Type	Method	Description
protected void	sxpInitialize()	Initialization proper to each propagator (SGP or SDP).
protected void	sxpPropagate(double tSince)	Propagation proper to each propagator (SGP or SDP).

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

Constructor Detail

SGP4

public SGP4(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

sxpInitialize

protected void sxpInitialize()

Initialization proper to each propagator (SGP or SDP).

Specified by:

sxpInitialize in class TLEPropagator

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 (min)