{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,30]],"date-time":"2026-03-30T17:59:04Z","timestamp":1774893544022,"version":"3.50.1"},"reference-count":23,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2022,7,13]],"date-time":"2022-07-13T00:00:00Z","timestamp":1657670400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>This work analyzes the observations from the Lunar Regolith Penetrating Radar (LRPR) onboard Chang\u2019E-5 to reconstruct the subsurface structure of the regolith under the lander at the drilling site. This is the first stationary Ground-Penetrating Radar (GPR) array to operate on the Moon. Imaging results of pre-drilling and post-drilling measurements show that the thickness of local regolith is larger than 2 m. Within the LRPR\u2019s detection range, we do not find any continuous layer. Instead, irregular, high-density zones are identified in the regolith. Two of these zones are on the drilling trajectory at ~30 cm and ~70 cm, consistent with the recorded drilling process. We speculate a rock fragment from the deeper, high-density zone obstructed the drill, which led to an early termination of the drilling. Based on our interpretation of subsurface structure, we modeled the LRPR echoes using a finite-difference time-domain method. The same imaging algorithm was also applied to the simulation data. The modeled data verify our inference of the regolith structure under the lander.<\/jats:p>","DOI":"10.3390\/rs14143378","type":"journal-article","created":{"date-parts":[[2022,7,14]],"date-time":"2022-07-14T00:12:40Z","timestamp":1657757560000},"page":"3378","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Shallow Regolith Structure and Obstructions Detected by Lunar Regolith Penetrating Radar at Chang\u2019E-5 Drilling Site"],"prefix":"10.3390","volume":"14","author":[{"given":"Jianqing","family":"Feng","sequence":"first","affiliation":[{"name":"Planetary Science Institute, Tucson, AZ 85719, USA"},{"name":"Department of Earth Sciences, Southern Methodist University, Dallas, TX 75205, USA"}]},{"given":"Matthew A.","family":"Siegler","sequence":"additional","affiliation":[{"name":"Planetary Science Institute, Tucson, AZ 85719, USA"},{"name":"Department of Earth Sciences, Southern Methodist University, Dallas, TX 75205, USA"}]},{"given":"Mackenzie N.","family":"White","sequence":"additional","affiliation":[{"name":"Planetary Science Institute, Tucson, AZ 85719, USA"},{"name":"Department of Earth Sciences, Southern Methodist University, Dallas, TX 75205, USA"}]}],"member":"1968","published-online":{"date-parts":[[2022,7,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Zheng, Y., Mengfei, Y., Xiangjin, D., Shengyi, J., Jing, P., Yan, S., Gu, Z., Chen, L., Pang, Y., and Zhang, N. 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