The WISDOM (Water Ice Subsurface Deposit Observation on Mars) Ground Penetrating Radar will fly on the ESA-NASA 2018 ExoMars-C mission, which combines the science payload of the original ESA ExoMars Rover with the robotic arm and sample cache of NASA's Max-C Rover into a single rover, whose samples will ult imately be retrieved by a future Mars Sample Return mission. WISDOM was designed to investigate the nearsubsurface down to a depth of ~2-3 m, commensurate with the sampling capabilit ies of the rover's drill. The information provided by WISDOM will assist in understanding the large-scale geology and history of the landing site, as well as selecting the most appropriate locations where to drill and collect sub surface samples for further analysis. Here we review the real-world performance of the instrument as experimentally observed in various field test environments.