Sounding Radar?
reading between the lines, the instrument for probing the depth of the Lunar regolith (aka "soil") will likely be a sounding radar. This will be interesting to compare with record from the ESA MARSIS radar - one from a known waterless heavily cratered body with a history of volcanism and the other from an icy heavily cratered body with a history of volcanism AND some other sedimentary processes - aeolian and whatever caused/causes the ancient "flood" channels and the more recent gullies.