Class FieldTLEPropagator<T extends CalculusFieldElement<T>>

  • Type Parameters:
    T - type of the field elements
    All Implemented Interfaces:
    FieldPropagator<T>, FieldPVCoordinatesProvider<T>, ParameterDriversProvider
    Direct Known Subclasses:
    FieldDeepSDP4, FieldSGP4

    public abstract class FieldTLEPropagator<T extends CalculusFieldElement<T>>
    extends FieldAbstractAnalyticalPropagator<T>
    This class provides elements to propagate TLE's.

    The models used are SGP4 and SDP4, initially proposed by NORAD as the unique convenient propagator for TLE's. Inputs and outputs of this propagator are only suited for NORAD two lines elements sets, since it uses estimations and mean values appropriate for TLE's only.

    Deep- or near- space propagator is selected internally according to NORAD recommendations so that the user has not to worry about the used computation methods. One instance is created for each TLE (this instance can only be get using selectExtrapolator(FieldTLE, CalculusFieldElement[]) method, and can compute position and velocity coordinates at any time. Maximum accuracy is guaranteed in a 24h range period before and after the provided TLE epoch (of course this accuracy is not really measurable nor predictable: according to CelesTrak, the precision is close to one kilometer and error won't probably rise above 2 km).

    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.

    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), Thomas Paulet (field translation)
    See Also: