TRIP (TRajectory Integration Program). Program Description and Use

摘要

The report describes a numerical integration computer program (called TRIP) based on Encke's method of integrating only the perturbations in the cartesian coordinates. The mathematical model can include Venus, Earth, Mars, Jupiter, the Moon, and the Sun as either central or disturbing bodies. In addition, full gravity field potentials are included for the Earth (7X7) and Moon(4X4) and J2 only for Mars. Modification to expand the gravity models for the other planets is simple. Solar radiation pressure may also be included as an option in the input. The program uses the latest exported JPL double-precision planetary ephemerides (DE 19). TRIP has the option of calculating shadow times of penumbra and umbra; printout may be obtained at specified times or, in the case of a planetary orbiter, at apoapsis or periapsis. Input data is very simple and there is a variety of coordinate systems for printout. (Author)