The measurement method for determination of the motion parameters of the module de-orbiting upon the lunar surface has been suggested. The surface-scattered gammas emitted by a radioactive source are detected using four receptors under uncertainty of the lunar-soil’s elemental composition. The radar-tracking system’s exist in the module allows adaptation of the gamma-ray altimeter to the lunar-soil composition. A mathematical model of the measuring system has been put forward, and dependences of the gammas’ flux level on the module altitude and the angle of the slanted surface were obtained. The model makes possible analyzing the relative position of the radioactive source and the receptors and the composition effect of the substrate. The measurement algorithm uses a recursive neural network, which is proposed to train in advance and adapt during the module landing.

Citation: I.A. Kislitsyna, G.F. Malykhina, Simulation of on-the-fly measuring system of a descent module under uncertainty of the lunar-surface composition, St. Petersburg Polytechnical State University Journal. Physics and Mathematics. 10 (3) (2017) 38–51. DOI: 10.18721/JPM.10304