Interpretation of lightcurves of atmosphereless bodies. II - Practical aspects of inversion

We have developed methods of inversion that can be used in the determination of the three-dimensional shape or the albedo distribution of the surface of a body from disk-integrated photometry, assuming the shape to be strictly convex (Kaasalainen et al., 1991). Here, we study the practical aspects of the inversion procedure. We also apply our methods to lightcurve data of 39 Laetitia and 16 Psyche. There are many observational factors having an influence on the outcome of inversion. Also, one must make some a priori assumptions that are used in the inversion process. The most important points are the number and range of the observing geometries, the assumed spin vector of the asteroid, possible large-scale nonconvexity of the surface, and the accuracy of the lightcurves. In an appendix, we also describe how the formalism we have presented can be used in generating arbitrary convex shapes conveniently and then in producing synthetic lightcurves efficiently with them.