Shapes and scattering properties of large irregular bodies from photometric data

The macroscopic shapes, rotational states, and scattering parameters of atm osphereless bodies can be deduced from photometric measurements of total br ightnesses in different viewing/illumination geometries. The problem is sol ved with nonlinear optimization techniques; the use of positive definite qu antities effectively removes the apparent ill-posedness of the problem. Sin ce the parameters of scattering laws such as the Hapke model cannot be unam biguously determined from photometric data only, we propose a simple empiri cal scattering model for he purpose. Our methods can obtain convex hull-lik e shapes even for strongly nonconvex objects; a conception of he major conc avities can also be formed. (C) 2001 Optical Society of America.