A Study of Shadow Representation for High-fidelity Solar Radiation Pressure Calculation

摘要

For a precise calculation of the solar radiation pressure force acting on a space vehicle, the effect of shadows casted by the spacecraft structure itself is a challenging issue. The calculation cost of the shadow effect for a high-fidelity geometrical model is too high to apply to a practical astrodynamics analysis. Thus, authors have proposed a pre-computed method for a fast and precise solar radiation calculation. In this method, the visibility function for each micro-surface is calculated beforehand and then expanded to a set of basis functions in an offline pre-computation stage. In the real-time calculation phase, the coefficients corresponding to the basis functions are used for fast and precise solar radiation computation. One of the key points of the proposed method is the selection of the basis functions, and this paper compares two major spherical basis functions for accurate and efficient shadow representation. Several calculation examples of the three-dimensional objects are demonstrated to evaluate the computational cost and accuracy of the proposed method. The examples show that the proposed method is capable of providing an efficient and accurate real-time solar radiation pressure computation with a capability of the optical property estimation.