Optimization Methods for Asteroid Lightcurve Inversion. II. The Complete Inverse Problem

The rotation period, pole direction, and scattering parameters of an asteroid can be deduced from its lightcurves simultaneously with the shape. Simulations and real data indicate that the result obtained with convex inversion is unique and stable if several lightcurves obtained at various geometries are available. Since the parameters of scattering laws such as the Hapke or Lumme-Bowell models cannot be determined well using lightcurves only, we introduce a simple empirical scattering law. This law can be applied in the computation of reference lightcurves and phase curves for further analysis of the physical properties of the surface. We present shape, pole, and period solutions for asteroids that have also been observed by space probes or radar.