Package org.orekit.propagation.semianalytical.dsst

Class DSSTHarvester

    • Method Detail

      • getB1

        public RealMatrix getB1()
        Get the Jacobian matrix B1 (B1 = ∂εη/∂Y).

        B1 represents the partial derivatives of the short period motion with respect to the mean equinoctial elements.

        Returns:
        the B1 jacobian matrix

      • getB2

        public RealMatrix getB2​(SpacecraftState state)
        Get the Jacobian matrix B2 (B2 = ∂Y/∂Y₀).

        B2 represents the partial derivatives of the mean equinoctial elements with respect to the initial ones.

        Parameters:
        state - spacecraft state
        Returns:
        the B2 jacobian matrix

      • getB3

        public RealMatrix getB3​(SpacecraftState state)
        Get the Jacobian matrix B3 (B3 = ∂Y/∂P).

        B3 represents the partial derivatives of the mean equinoctial elements with respect to the estimated propagation parameters.

        Parameters:
        state - spacecraft state
        Returns:
        the B3 jacobian matrix

      • getB4

        public RealMatrix getB4()
        Get the Jacobian matrix B4 (B4 = ∂εη/∂c).

        B4 represents the partial derivatives of the short period motion with respect to the estimated propagation parameters.

        Returns:
        the B4 jacobian matrix

      • freezeColumnsNames

        public void freezeColumnsNames()
        Freeze the names of the Jacobian columns.

        This method is called when proagation starts, i.e. when configuration is completed

        Specified by:
        freezeColumnsNames in class AbstractMatricesHarvester

      • getJacobiansColumnsNames

        public List<String> getJacobiansColumnsNames()
        Get the names of the parameters in the matrix returned by MatricesHarvester.getParametersJacobian(org.orekit.propagation.SpacecraftState).

        Beware that the names of the parameters are fully known only once all force models have been set up and their parameters properly selected. Applications that retrieve the matrices harvester first and select the force model parameters to retrieve afterwards (but obviously before starting propagation) must take care to wait until the parameters have been set up before they call this method. Calling the method too early would return wrong results.

        The names are returned in the Jacobians matrix columns order

        Returns:
        names of the parameters (i.e. columns) of the Jacobian matrix

      • initializeFieldShortPeriodTerms

        public void initializeFieldShortPeriodTerms​(SpacecraftState reference)
        Initialize the short periodic terms for the "field" elements.
        Parameters:
        reference - current mean spacecraft state

      • initializeFieldShortPeriodTerms

        public void initializeFieldShortPeriodTerms​(SpacecraftState reference,
                                            PropagationType type)
        Initialize the short periodic terms for the "field" elements.
        Parameters:
        reference - current mean spacecraft state
        type - MEAN or OSCULATING

      • updateFieldShortPeriodTerms

        public void updateFieldShortPeriodTerms​(SpacecraftState reference)
        Update the short periodic terms for the "field" elements.
        Parameters:
        reference - current mean spacecraft state

      • setReferenceState

        public void setReferenceState​(SpacecraftState reference)
        Set up reference state.

        This method is called whenever the global propagation reference state changes. This corresponds to the start of propagation in batch least squares orbit determination or at prediction step for each measurement in Kalman filtering. Its goal is to allow the harvester to compute some internal data. Analytical models like TLE use it to compute analytical derivatives, semi-analytical models like DSST use it to compute short periodic terms, numerical models do not use it at all.

        Specified by:
        setReferenceState in interface MatricesHarvester
        Overrides:
        setReferenceState in class AbstractMatricesHarvester
        Parameters:
        reference - reference state to set

      • getOrbitType

        public OrbitType getOrbitType()
        Get the orbit type used for the matrix computation.
        Returns:
        the orbit type used for the matrix computation