WISDOM prototype main units
WISDOM (Water Ice and Subsurface Deposit Observation on Mars), a subsurface sounding radar, is one of the instruments that will be carried by the ExoMars rover instrument suite. WISDOM will provide a detailed view of the structure of the subsurface of the Red Planet by studying the upper layers of the Martian crust.
To map the layers of the planet's subsurface, WISDOM will use a UHF ground penetrating radar. The instrument consists of two main units: the electronic unit (left) and the antenna system (right) with the latter facing downwards to sound the subsurface. The antennas will be covered in thin dielectric foil to protect them from Martian dust particles.
WISDOM transmits and receives signals in a frequency range from 500 MHz to 3 GHz. Wherever there is a sudden transition in the electrical properties of the ground, the electromagnetic waves emitted by the radar are reflected back towards the antennas. These reflections are used to map the subsurface.