{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,5]],"date-time":"2026-02-05T06:51:37Z","timestamp":1770274297336,"version":"3.49.0"},"reference-count":21,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2023,1,28]],"date-time":"2023-01-28T00:00:00Z","timestamp":1674864000000},"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>The SHAllow RADar (SHARAD) onboard Mars Reconnaissance Orbiter (MRO) is a 20 MHz Synthetic Aperture Radar (SAR) that probes the first hundreds of meters of the Martian subsurface. In order to interpret the detection of subsurface interfaces with ground penetrating radars, simulations using Digital Terrain Models (DTM) are necessary. This methodology paper focuses on the analysis of the first tens of meters of the Martian subsurface with SHARAD, comparing the use of different high-resolution DTMs for radar simulation, namely, from the High-Resolution Stereo Camera (HRSC) onboard the Mars Express and from the Context Camera (CTX) onboard MRO. The region of Terra Cimmeria was chosen as a demonstration area. It is a highly cratered southern midlatitude region, where, as will be discussed, the higher resolution of the aforementioned terrain models is mandatory to describe the surface at an acceptable level of detail for shallow subsurface radar interpretation. With a DTM corrected by photoclinometry using CTX imagery, we show that a reflector that was visible on SHARAD data but not on the simulation made with an HRSC DTM is, in fact, a surface echo that was not reproduced by the HRSC surface model. We also show that, unlike laser altimetry DTMs, optical DTMs are prone to artifacts that can make radar analysis more complicated for some scenarios. Reciprocally, we show that the comparison between radar and its corresponding simulated data is a way of assessing a DTM\u2019s quality, which is especially useful in missions where ground control points are lacking, unlike Martian observations.<\/jats:p>","DOI":"10.3390\/rs15030764","type":"journal-article","created":{"date-parts":[[2023,1,30]],"date-time":"2023-01-30T10:19:28Z","timestamp":1675073968000},"page":"764","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Resolving Ambiguities in SHARAD Data Analysis Using High-Resolution Digital Terrain Models"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2748-539X","authenticated-orcid":false,"given":"L\u00e9opold","family":"Desage","sequence":"first","affiliation":[{"name":"Universit\u00e9 Grenoble Alpes, CNRS, CNES, IPAG, 38000 Grenoble, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3699-883X","authenticated-orcid":false,"given":"Alain","family":"Herique","sequence":"additional","affiliation":[{"name":"Universit\u00e9 Grenoble Alpes, CNRS, CNES, IPAG, 38000 Grenoble, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3130-5336","authenticated-orcid":false,"given":"Sylvain","family":"Dout\u00e9","sequence":"additional","affiliation":[{"name":"Universit\u00e9 Grenoble Alpes, CNRS, CNES, IPAG, 38000 Grenoble, France"}]},{"given":"Sonia","family":"Zine","sequence":"additional","affiliation":[{"name":"Universit\u00e9 Grenoble Alpes, CNRS, CNES, IPAG, 38000 Grenoble, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6744-8796","authenticated-orcid":false,"given":"Wlodek","family":"Kofman","sequence":"additional","affiliation":[{"name":"Universit\u00e9 Grenoble Alpes, CNRS, CNES, IPAG, 38000 Grenoble, France"},{"name":"Centrum Badan Kosmicznych Polskiej Akademii Nauk (CBK PAN), Bartycka 18A, PL-00\u2013716 Warsaw, Poland"}]}],"member":"1968","published-online":{"date-parts":[[2023,1,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"454","DOI":"10.1016\/j.icarus.2009.01.009","article-title":"MARSIS Surface Reflectivity of the South Residual Cap of Mars","volume":"201","author":"Mouginot","year":"2009","journal-title":"Icarus"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1126\/science.1139672","article-title":"Subsurface Radar Sounding of the South Polar Layered Deposits of Mars","volume":"316","author":"Plaut","year":"2007","journal-title":"Science"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1235","DOI":"10.1126\/science.1164246","article-title":"Radar Sounding Evidence for Buried Glaciers in the Southern Mid-Latitudes of Mars","volume":"322","author":"Holt","year":"2008","journal-title":"Science"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"230","DOI":"10.1038\/s41550-020-01290-z","article-title":"Availability of Subsurface Water-Ice Resources in the Northern Mid-Latitudes of Mars","volume":"5","author":"Morgan","year":"2021","journal-title":"Nat. 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