First measurements in LUNA hall: Imaging the deep floor area with radar waves

For two days, researchers from the Chair of Radio Frequency and Photonics Engineering at TU Dresden performed ground-penetrating radar (GPR) measurements in the LUNA hall. The group is involved in GPR experiments e.g. on NASA’s Mars rover Perserverance and the rover of the upcoming ESA ExoMars mission (scheduled launch in 2028). GPR has already been applied on the Moon to image the uppermost 10s of meters of the subsurface in high resolution, using reflected echoes of radar waves broadcast from an antenna. For future lunar missions to the lunar South Pole, this method is for example of special interest for the detection of water ice. Finding water ice is also the aim of the international ESA topical team “Polar Explorer” led by the DLR Institute for Planetary Science, which is designing a rover mission to the Moon and planning to conducts tests in LUNA by the end of this year. The topical team includes the researchers from Dresden as well as from MUSC.

The goal of the reference measurements in LUNA without regolith filling is the detailed characterization of echoes from the concrete floor of the building – especially within the deep floor area (DFA). This will allow to better recognize the effects of the regolith later on, and to determine its properties (e.g. damping of the radar waves). The GPR measurements marked the first successful use of the overhead traveling crane in LUNA, requiring smooth speed and centimeter-scale precision. The position of the measurement device was also tracked by LIDAR. The test of several different antenna configurations helps to determine which one works best for mapping LUNA. Additionally, the response of a target body that will be buried within the regolith in the DFA was measured, so that its radar echo is well-known.