Subsurface Radar Sounding of the Jovian Moon Ganymede

This paper provides an overview of the Europa Jupiter System Mission (EJSM) and of its scientific objectives, focusing the attention on the subsurface radar (SSR) instrument included in the model payload of the Jupiter Ganymede Orbiter (JGO). The SSR instrument is a radar sounder system at low frequency (HF/VHF band) designed to penetrate the surface of Ganymede icy moon of Jupiter for performing a subsurface analysis with a relatively high range resolution. This active instrument is aimed at acquiring information on the Ganymede (and partially on the Callisto during flybys) shallow subsurface. The paper addresses the main issues related to SSR, presenting its scientific goals, describing the concept and the design procedure of the instrument, and illustrating the signal processing techniques. Despite the fact that SSR can be defined on the basis of the heritage of the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) and SHAllow RADar (SHARAD) instruments currently o...