A Direct Light Curve Inversion Scheme in the Presence of Measurement Noise

Shape and attitude of resident space objects directly affect the orbit propagation via drag and solar radiation pressure. Obtaining information beyond an object state is integral to identifying an object, aid in tracing its origin and its capabilities. For objects that have a significant distance to the observer, only non-resolved imaging is available, which does not reveal any details of the object. So-called non-resolved light curve measurements, i.e. brightness measurements over time, can be used to determine the shape of convex space objects using an inversion scheme. The inversion process starts by first determining the Extended Gaussian Image and then solving Minkowski problem to obtain the closed shape result. In this paper, the effect of measurement noise on the shape inversion and the influence of the measurement geometry is investigated. Despite the presence of measurement noise, in a new methodology, expanding upon established inversion techniques, almost perfect inversion results can be obtained in a two-step process: first, an initial light curve is used for shape hypothesis creation, and then, a second (potentially very short) light curve is used for selection of the best hypothesis. Results are shown for two standard shapes of a cuboid and a house shape.