Muinonen, KarriKarriMuinonenWilkman, OlliOlliWilkmanCELLINO, AlbertoAlbertoCELLINOWang, XiaobinXiaobinWangWang, YiboYiboWang2020-05-132020-05-1320150032-0633http://hdl.handle.net/20.500.12386/24805Acknowledgments Constructive comments from the anonymous referees helped improve the original paper. Research supported, in part, by the Academy of Finland (Project 1257966).We derive initial rotation, shape, and scattering properties for asteroids from sparse and dense photometry based on the so-called Lommel-Seeliger ellipsoid (LS ellipsoid). Due to the analytical disk-integrated brightness, the LS ellipsoid allows for fast rotation-period, pole-orientation, and shape analyses, as well as efficient Markov-chain Monte Carlo solutions (MCMC). We apply the methods to simulated sparse Gaia photometry, as well as to ground-based photometry composed of dense lightcurves. For a specific Gaia simulation, we make use of a numerical reflection coefficient developed for particulate surfaces, and utilize the LS ellipsoid in the inversion of the simulated data. We conclude that, in a majority of cases, initial LS ellipsoid retrieval of the parameters is satisfactory. Finally, we formulate a single-scattering phase function that, for a spherical asteroid, results in the H ,G<SUB>1</SUB> ,G<SUB>2</SUB> photometric phase function. <P />STAMPAenArticle10.1016/j.pss.2015.09.0052-s2.0-84951299337000370460100028https://www.sciencedirect.com/science/article/pii/S0032063315002548?via%3Dihub2015P&SS..118..227MFIS/05 - ASTRONOMIA E ASTROFISICA