Laser Altimetry on Bepi Colombo

Kurzfassung

A consortium led by Physikalisches Institut, Universität Bern und and the DLR Institut für Planetenforschung Berlin will be proposing a Laser Altimeter for the upcoming Bepi Colombo mission to Mercury. The Laser Altimeter will be measuring the figure of the planet to 10 m accurcacy and the topography to an accuracy of 1 m with a grid spacing of a few hundred meter along-track. In addition, attempts will be made to measure the tidal deformation of the planet which, as calculations have shown, should be on the order of a meter. The Laser Altimeter data will also provide constraints on the surface roughness from the divergence of the reflected laser signal, terrain slopes, and the surface albedo. It is even possible that the Laser Altimeter may provide contraints of the possible existence of ice in permanently shaded craters near the poles. Here, the Laser Altimeter will profit from providing its own illumination source. The instrument will work synergetically with both the radio science experience and the stereo camera on Bepi Colombo. The radio science experiment will measure the gravity field. The Laser Altimeter topography data will be used to correct these measurements for the effects of surface topography and thereby allow a more reliable assessment of the interior structure of the planet including the lateral variations of the crust thickness and of the core radius. The Laser Altimeter and the stereo camera will work together to provide an accurate digital terrain model. This model will be used to assess the morphology, the volcanism and the tectonics of the planet. Prominent features of the topography know to us today such as lobate scarps will be measured accurately and provide important constraints on the cooling history of the planet.