boinor.core.propagation.gooding

module related to propagation of an orbit using Gooding’s method in the core sub-package

Functions

gooding_coe_parabolic(k, p, ecc, inc, raan, argp, nu, tof)

not yet implemented propagation with Gooding's method for parabolic case

gooding_coe_hyperbolic(k, p, ecc, inc, raan, argp, nu, tof)

not yet implemented propagation with Gooding's method for hyperbolic case

gooding_coe_elliptic(k, p, ecc, inc, raan, argp, nu, tof)

This function contains EKEPL1 from appendix A of Walker et al. [WIO85]

gooding_coe(k, p, ecc, inc, raan, argp, nu, tof[, ...])

This function is just a wrapper for the correct ecc handling.

gooding(k, r0, v0, tof[, numiter, rtol])

Solves the Elliptic Kepler Equation with a cubic convergence and

Module Contents

boinor.core.propagation.gooding.gooding_coe_parabolic(k, p, ecc, inc, raan, argp, nu, tof, numiter=150, rtol=1e-08)

not yet implemented propagation with Gooding’s method for parabolic case

boinor.core.propagation.gooding.gooding_coe_hyperbolic(k, p, ecc, inc, raan, argp, nu, tof, numiter=150, rtol=1e-08)

not yet implemented propagation with Gooding’s method for hyperbolic case

boinor.core.propagation.gooding.gooding_coe_elliptic(k, p, ecc, inc, raan, argp, nu, tof, numiter=150, rtol=1e-08)

This function contains EKEPL1 from appendix A of Walker et al. [WIO85] As mentioned in this paper, it uses a Legendre based starter and a Halley iterator

boinor.core.propagation.gooding.gooding_coe(k, p, ecc, inc, raan, argp, nu, tof, numiter=150, rtol=1e-08)

This function is just a wrapper for the correct ecc handling.

boinor.core.propagation.gooding.gooding(k, r0, v0, tof, numiter=150, rtol=1e-08)

Solves the Elliptic Kepler Equation with a cubic convergence and accuracy better than 10e-12 rad is normally achieved. It is not valid for eccentricities equal or higher than 1.0.

Parameters:

  • k (float) – Standard gravitational parameter of the attractor.

  • r0 (numpy.ndarray) – Position vector.

  • v0 (numpy.ndarray) – Velocity vector.

  • tof (float) – Time of flight.

  • numiter (int, optional) – Number of iterations, defaults to 150.

  • rtol (float, optional) – Relative error for accuracy of the method, defaults to 1e-8.

Returns:

  • rr (numpy.ndarray) – Final position vector.

  • vv (numpy.ndarray) – Final velocity vector.

Note

Original paper for the algorithm: https://doi.org/10.1007/BF01238923 This is Walker et al. [WIO85].