The Mars rover subsurface penetrating radar onboard China's Mars 2020 mission

Abstract

China's Mars probe, named Tianwen-1, including an orbiter and a landing rover, will be launched during the July-August 2020 Mars launch windows. Selected to be among the rover payloads is a Subsurface Penetrating Radar module (RoSPR). The main scientific objective of the RoSPR is to characterize the thickness and sub-layer distribution of the Martian soil. The RoSPR consists of two channels. The low frequency channel of the RoSPR will penetrate the Martian soil to depths of 10 to 100 m with a resolution of a few meters. The higher frequency channel will penetrate to a depth of 3 to 10 m with a resolution of a few centimeters. This paper describes the design of the instrument and some results of field experiments.

Ground-Penetrating Radar Modeling Across the Jezero Crater Floor

“…Depth axes correspond to a constant medium velocity of 0.12 m/ns, for a radar located 0.6 m above ground. The detection limit is at the -147 dB noise level defined according to (3).…”

“…The top surface of the LTF is generated by extrapolating its wavy surface topography into the ground, with additional 0.5m fractal roughness, while the delta has a smooth and dipping top surface with 0.1m fractal roughness. The aeolian dunes and the unconsolidated layer mantling the mafic unit are assumed to have low densities (1.1 and 1.3 g/cm 3 , respectively) in the range of in-situ measurements done by the Viking lander [73]. This corresponds to low dielectric constants (ε'=2.1 and ε'=2.4) and losses (ε''=0.06 and ε''=0.07, at the centre frequency) according to measurements of the soil simulant JSC-1 [15].…”

“…The ground penetrating radar (GPR) will take measurements every 10 cm along the drive path, unveiling subsurface structures, bedding and stratigraphic relationships. In like manner, GPRs are also included among the scientific payload for the Chinese Tianwen-1 mission [3] (launched in 2020) and the upcoming European-Russian ExoMars mission [4] (planned for launch in 2022). Improved understanding of Martian geology will be achieved through radar sounding during the next decade of Martian exploration.…”

Design and Validation of the Scientific Data Products for China’s Tianwen-1 Mission

“…Additionally, six instruments are onboard the rover to perform high-accuracy and highresolution investigations of the Mars landing site, mainly including investigation of morphological features, subsurface geological structures, minerals and chemical composition, climate and environmental characteristics, and spatial magnetic field. The instrument configuration and data descriptions of the rover are listed in Table 2 (Peng et al 2020;Zhou et al 2020;Du et al 2020).…”

“…The processing procedures of each instrument are given in Table 3. The more detailed information about calibration is published in the overview of each instrument (Tang et al 2020;Yu et al 2020;Kong et al 2020;Liang et al 2021;Meng et al 2021;Fan et al 2021;He et al 2021;Du et al 2020;Peng et al 2020;Zhou et al 2020).…”