{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,27]],"date-time":"2026-05-27T19:30:51Z","timestamp":1779910251226,"version":"3.53.1"},"reference-count":69,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2020,7,14]],"date-time":"2020-07-14T00:00:00Z","timestamp":1594684800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000038","name":"Natural Sciences and Engineering Research Council of Canada","doi-asserted-by":"publisher","award":["Research Program"],"award-info":[{"award-number":["Research Program"]}],"id":[{"id":"10.13039\/501100000038","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Canadian Polar Knowledge program","award":["CHARS"],"award-info":[{"award-number":["CHARS"]}]},{"name":"France-Quebec collaborative program","award":["CFQCU"],"award-info":[{"award-number":["CFQCU"]}]},{"DOI":"10.13039\/501100004796","name":"Institut Polaire Fran\u00e7ais Paul Emile Victor","doi-asserted-by":"publisher","award":["Antarctica Field Work"],"award-info":[{"award-number":["Antarctica Field Work"]}],"id":[{"id":"10.13039\/501100004796","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003151","name":"Fonds de recherche du Qu\u00e9bec \u2013 Nature et technologies","doi-asserted-by":"publisher","award":["France-Qu\u00e9bec"],"award-info":[{"award-number":["France-Qu\u00e9bec"]}],"id":[{"id":"10.13039\/501100003151","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003151","name":"Fonds de recherche du Qu\u00e9bec \u2013 Nature et technologies","doi-asserted-by":"publisher","award":["Regroupement Strat\u00e9gique CEN"],"award-info":[{"award-number":["Regroupement Strat\u00e9gique CEN"]}],"id":[{"id":"10.13039\/501100003151","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Monitoring the evolution of snow on the ground and lake ice\u2014two of the most important components of the changing northern environment\u2014is essential. In this paper, we describe a lightweight, compact and autonomous 24 GHz frequency-modulated continuous-wave (FMCW) radar system for freshwater ice thickness and snow mass (snow water equivalent, SWE) measurements. Although FMCW radars have a long-established history, the novelty of this research lies in that we take advantage the availability of a new generation of low cost and low power requirement units that facilitates the monitoring of snow and ice at remote locations. Test performance (accuracy and limitations) is presented for five different applications, all using an automatic operating mode with improved signal processing: (1) In situ lake ice thickness measurements giving 2 cm accuracy up to \u22481 m ice thickness and a radar resolution of 4 cm; (2) remotely piloted aircraft-based lake ice thickness from low-altitude flight at 5 m; (3) in situ dry SWE measurements based on known snow depth, giving 13% accuracy (RMSE 20%) over boreal forest, subarctic taiga and Arctic tundra, with a measurement capability of up to 3 m in snowpack thickness; (4) continuous monitoring of surface snow density under particular Antarctic conditions; (5) continuous SWE monitoring through the winter with a synchronized and collocated snow depth sensor (ultrasonic or LiDAR sensor), giving 13.5% bias and 25 mm root mean square difference (RMSD) (10%) for dry snow. The need for detection processing for wet snow, which strongly absorbs radar signals, is discussed. An appendix provides 24 GHz simulated effective refractive index and penetration depth as a function of a wide range of density, temperature and wetness for ice and snow.<\/jats:p>","DOI":"10.3390\/s20143909","type":"journal-article","created":{"date-parts":[[2020,7,14]],"date-time":"2020-07-14T09:30:49Z","timestamp":1594719049000},"page":"3909","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":31,"title":["Low Cost and Compact FMCW 24 GHz Radar Applications for Snowpack and Ice Thickness Measurements"],"prefix":"10.3390","volume":"20","author":[{"given":"Patrick","family":"Pomerleau","sequence":"first","affiliation":[{"name":"Centre d\u2019Applications et de Recherches en T\u00e9l\u00e9d\u00e9tection (CARTEL), Universit\u00e9 de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6593-2007","authenticated-orcid":false,"given":"Alain","family":"Royer","sequence":"additional","affiliation":[{"name":"Centre d\u2019Applications et de Recherches en T\u00e9l\u00e9d\u00e9tection (CARTEL), Universit\u00e9 de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada"},{"name":"Centre d\u2019\u00c9tudes Nordiques, Qu\u00e9bec, QC G1V 0A6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexandre","family":"Langlois","sequence":"additional","affiliation":[{"name":"Centre d\u2019Applications et de Recherches en T\u00e9l\u00e9d\u00e9tection (CARTEL), Universit\u00e9 de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada"},{"name":"Centre d\u2019\u00c9tudes Nordiques, Qu\u00e9bec, QC G1V 0A6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Patrick","family":"Cliche","sequence":"additional","affiliation":[{"name":"Centre d\u2019Applications et de Recherches en T\u00e9l\u00e9d\u00e9tection (CARTEL), Universit\u00e9 de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bruno","family":"Courtemanche","sequence":"additional","affiliation":[{"name":"Centre d\u2019Applications et de Recherches en T\u00e9l\u00e9d\u00e9tection (CARTEL), Universit\u00e9 de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jean-Beno\u00eet","family":"Madore","sequence":"additional","affiliation":[{"name":"Centre d\u2019Applications et de Recherches en T\u00e9l\u00e9d\u00e9tection (CARTEL), Universit\u00e9 de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1475-5853","authenticated-orcid":false,"given":"Ghislain","family":"Picard","sequence":"additional","affiliation":[{"name":"Institut des G\u00e9osciences de l\u2019Environnement (IGE), CNRS Universit\u00e9 Grenoble Alpes, 38 058 Grenoble, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"\u00c9ric","family":"Lefebvre","sequence":"additional","affiliation":[{"name":"Institut des G\u00e9osciences de l\u2019Environnement (IGE), CNRS Universit\u00e9 Grenoble Alpes, 38 058 Grenoble, France"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,7,14]]},"reference":[{"key":"ref_1","unstructured":"(2006, July 12). Canada Red Cross. Available online: https:\/\/www.redcross.ca."},{"key":"ref_2","unstructured":"(2019, July 12). IPCC Special Report on the Ocean and Cryosphere in a Changing Climate. Available online: https:\/\/www.ipcc.ch\/srocc\/chapter\/chapter-3-2\/."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1016\/j.advwatres.2012.08.010","article-title":"Small scale spatial variability of snow density and depth over complex alpine terrain: Implications for estimating snow water equivalent","volume":"55","author":"Fassnacht","year":"2013","journal-title":"Adv. Water Resour."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"872","DOI":"10.1080\/02626667.2010.503933","article-title":"Simulation hydrologique des derniers jours de la crue de printemps: Le probl\u00e8me de la neige manquante","volume":"55","author":"Turcotte","year":"2010","journal-title":"Hydrol. Sci. J."},{"key":"ref_5","unstructured":"WMO-GCW (2015). Global Cryosphere Watch (GCW) Implementation Plan, Version 1.6, WMO. World Meteorological Organization Report."},{"key":"ref_6","unstructured":"(2017, July 12). AMAP and the Arctic Council. Available online: https:\/\/www.amap.no."},{"key":"ref_7","unstructured":"(2013, July 12). Observations: Cryosphere, in Climate Change 2013: The Physical Science Basis. Available online: https:\/\/www.ipcc.ch\/site\/assets\/uploads\/2018\/02\/WG1AR5_Chapter04_FINAL.pdf."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1016\/j.gloplacha.2011.03.004","article-title":"Processes and impacts of Arctic amplification. A research synthesis","volume":"77","author":"Serreze","year":"2011","journal-title":"Glob. Planet. Chang."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1929","DOI":"10.1002\/hyp.7565","article-title":"Analysis of snow cover variability and change in Quebec","volume":"24","author":"Brown","year":"2010","journal-title":"Hydrol. Processes"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"303","DOI":"10.1038\/nature04141","article-title":"Potential impacts of a warming climate on water availability in snow-dominated regions","volume":"438","author":"Barnett","year":"2005","journal-title":"Nature"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"811","DOI":"10.1175\/BAMS-D-11-00052.1","article-title":"How well are we measuring snow: The NOAA\/FAA\/NCAR winter precipitation test bed","volume":"93","author":"Rasmussen","year":"2012","journal-title":"Am. Meteorol. Soc."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1579","DOI":"10.5194\/tc-14-1579-2020","article-title":"Evaluation of long-term Northern Hemisphere snow water equivalent products","volume":"14","author":"Mortimer","year":"2020","journal-title":"Cryosphere"},{"key":"ref_13","unstructured":"Natural Resources Conservation Service (NRCS) (2020, June 01). Available online: https:\/\/www.nrcs.usda.gov."},{"key":"ref_14","unstructured":"British Columbia Network (2020, June 01). Snow Survey Data and Automated Snow Weather Station Data in British Columbia, Ca, Available online: https:\/\/www2.gov.bc.ca."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1080\/07055900.2019.1598843","article-title":"Update of Canadian historical snow survey data and analysis of snow water equivalent trends, 1967\u20132016","volume":"57","author":"Brown","year":"2019","journal-title":"Atmos. Ocean"},{"key":"ref_16","unstructured":"Choquette, Y., Ducharme, P., and Rogoza, J. (2013, January 7\u201311). CS725, an accurate sensor for the snow water equivalent and soil moisture measurements. Proceedings of the International Snow Science Workshop, Grenoble, France."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"045204","DOI":"10.1088\/1748-9326\/6\/4\/045204","article-title":"Changes in snow cover characteristics over Northern Eurasia since 1966","volume":"6","author":"Bulygina","year":"2011","journal-title":"Environ. Res. Lett."},{"key":"ref_18","first-page":"428","article-title":"New snow water equivalent processing system with improved resolution over Europe and its applications in hydrology","volume":"10","author":"Takala","year":"2017","journal-title":"IEEE J-STARS"},{"key":"ref_19","unstructured":"Gottardi, F., Carrier, P., Paquet, E., Laval, M.-T., Gailhard, J., and Gar\u00e7on, R. (2013, January 7\u201311). Le NRC: Une d\u00e9cennie de mesures\u2028de l\u2019\u00e9quivalent en eau du manteau neigeux dans les massifs montagneux fran\u00e7ais. Proceedings of the International Snow Science Workshop Grenoble, Chamonix Mont-Blanc, France."},{"key":"ref_20","unstructured":"Holmes, R.M., Shiklomanov, A.I., Suslova, A., Tretiakov, M., McClelland, J.W., Spencer, R.G.M., and Tank, S.E. (2020, June 01). Arctic River Discharge. Arctic Report 2018 Cards, Available online: https:\/\/arctic.noaa.gov\/Report-Card."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"840","DOI":"10.1109\/8.301704","article-title":"Ultra-Wideband Impulse Scattering Measurements","volume":"42","author":"Morgan","year":"1994","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"509","DOI":"10.3189\/2014JoG13J084","article-title":"Continuous snowpack monitoring using upward-looking ground-penetrating radar technology","volume":"60","author":"Schmid","year":"2014","journal-title":"J. Glaciol."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Nobes, D.C. (2011). Ground Penetrating Radar Measurements Over Glaciers. Encyclopedia of Snow, Ice and Glaciers, Springer.","DOI":"10.1007\/978-90-481-2642-2_230"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1109\/36.45751","article-title":"Signal-processing algorithm for the extraction of thin freshwater-ice thickness from short pulse radar data","volume":"28","author":"Riek","year":"1990","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_25","unstructured":"MALA\u00c5 Geoscience (2020, June 01). (n.d.). Case Studies for GPR in Geophysical Surveys, Available online: http:\/\/www.malags.com\/getattachment\/465a6999-c36c-46bc-80bc-2183c3b7ebb0\/Case-Studies-1."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Peng, Z., and Li, C. (2019). Portable Microwave Radar Systems for Short-Range Localization and Life Tracking: A Review. Sensors, 19.","DOI":"10.3390\/s19051136"},{"key":"ref_27","unstructured":"Schneider, M. (2005, January 5\u20137). Automotive radar\u2014Status and trends. Proceedings of the German Microwave Conference, Ulm, Germany."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"225","DOI":"10.3189\/S0022143000010765","article-title":"Snow Stratigraphy and Water Equivalence Measured with an Active Microwave System","volume":"26","author":"Ellerbruch","year":"1980","journal-title":"J. Glaciol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1016\/j.coldregions.2007.04.008","article-title":"FMCW radars for snow research","volume":"52","author":"Marshall","year":"2008","journal-title":"Cold Reg. Sci. Technol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1016\/j.coldregions.2004.06.005","article-title":"Alpine snow depth measurements from aerial FMCW radar","volume":"40","author":"Yankielun","year":"2004","journal-title":"Cold Reg. Sci. Technol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"207","DOI":"10.3189\/1985AoG6-1-207-210","article-title":"Snow stratigraphy measured by an active microwave sensor","volume":"6","author":"Fujino","year":"1985","journal-title":"Ann. Glaciol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"157","DOI":"10.3189\/172756405781813500","article-title":"Estimating alpine snowpack properties using FMCW radar","volume":"40","author":"Marshall","year":"2005","journal-title":"Ann. Glaciol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1609","DOI":"10.1002\/(SICI)1099-1085(199612)10:12<1609::AID-HYP504>3.0.CO;2-O","article-title":"Snow cover characterization using multiband FMCW radars","volume":"10","author":"Koh","year":"1996","journal-title":"Hydrol. Process."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"834","DOI":"10.1109\/TGRS.2016.2616134","article-title":"Ultrawideband FMCW Radar for Airborne Measurements of Snow Over Sea Ice and Land","volume":"55","author":"Yan","year":"2017","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Ghosh, G., and Chakravarty, D. (2019, January 7\u201312). Circularly Polarized Proximity Feed Patch Antenna for FMCW Radar. Proceedings of the 2019 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, Atlanta, GA, USA.","DOI":"10.1109\/APUSNCURSINRSM.2019.8888938"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"2689","DOI":"10.5194\/tc-12-2689-2018","article-title":"Multi-channel and multi-polarization radar measurements around the NEEM site","volume":"12","author":"Li","year":"2018","journal-title":"Cryosphere"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1016\/0165-232X(84)90003-X","article-title":"The use of microwave FMCW radar in snow and avalanche research","volume":"9","author":"Gubler","year":"1984","journal-title":"Cold Reg. Sci. Technol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1049\/ecej:19900043","article-title":"New ideas in FM radar","volume":"2","author":"Griffiths","year":"1990","journal-title":"Electron. Commun. Eng. J."},{"key":"ref_39","first-page":"342","article-title":"Linear FMCW radar techniques","volume":"139","author":"Stove","year":"1992","journal-title":"IEEE Proc. F."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"2824","DOI":"10.1109\/TGRS.2013.2266415","article-title":"Advanced multifrequency radar instrumentation for polar research","volume":"52","author":"Gogineni","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Hu, X., Ma, C., Hu, R., and Yeo, T.S. (2019). Imaging for Small UAV-Borne FMCW SAR. Sensors, 19.","DOI":"10.3390\/s19010087"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"3519","DOI":"10.1109\/TGRS.2007.906140","article-title":"Signal processing for FMCW SAR","volume":"45","author":"Meta","year":"2007","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"854","DOI":"10.1109\/TGRS.2016.2616441","article-title":"Millimeter-Wave Radar Sensor for Snow Height Measurements","volume":"55","author":"Ayhan","year":"2017","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/j.coldregions.2014.03.006","article-title":"Upward-looking L-band FMCW radar for snow cover monitoring","volume":"103","author":"Okorn","year":"2014","journal-title":"Cold Reg. Sci. Technol."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"727","DOI":"10.1002\/grl.50134","article-title":"High-resolution radar measurements of snow avalanches","volume":"40","author":"Vriend","year":"2013","journal-title":"Geophys. Res. Lett."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1016\/j.coldregions.2006.08.008","article-title":"Snow stratigraphy measurements with high-frequency FMCW radar: Comparison with snow micro-penetrometer","volume":"47","author":"Marshall","year":"2007","journal-title":"Cold Reg. Sci. Technol."},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Xu, X., Baldi, C., Bleser, J.-W., Lei, Y., Yueh, S., and Esteban-Fernandez, D. (2018, January 22\u201327). Multi-Frequency Tomography Radar Observations of Snow Stratigraphy at Fraser During SnowEx. Proceedings of the IGARSS 2018-2018 IEEE International Geoscience and Remote Sensing Symposium, Valencia, Spain.","DOI":"10.1109\/IGARSS.2018.8519538"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1016\/j.coldregions.2015.09.012","article-title":"Freshwater Lake Ice Thickness Derived Using Surface-based X- and Ku-band FMCW Scatterometers","volume":"120","author":"Gunn","year":"2015","journal-title":"Cold Reg. Sci. Technol."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1057","DOI":"10.1139\/l93-136","article-title":"Development of an airborne millimeter-wave FM-CW radar for mapping river ice","volume":"20","author":"Yankielun","year":"1993","journal-title":"Can. J. Civ. Eng."},{"key":"ref_50","unstructured":"Rodriguez, S., Marshall, H.P., and Rodriguez, P. (October, January 28). Applications of low cost and low power FMCW radar in the characterization of dry snow. Proceedings of the International Snow Science Workshop, Banff, UK."},{"key":"ref_51","unstructured":"(2020, June 01). IMST sentireTM Radar Module 24 GHz sR-1200 Series User Manual. Available online: http:\/\/www.radar-sensor.com\/."},{"key":"ref_52","unstructured":"Ulaby, F.T., Moore, R.K., and Fung, A.K. (1986). 1981, 1982, 1986: Microwave Remote Sensing, Active and Passive, Artech House, Inc."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1623","DOI":"10.1088\/0022-3727\/20\/12\/013","article-title":"Dielectric Properties of freshwater ice at microwave frequencies","volume":"20","author":"Wegmuller","year":"1987","journal-title":"J. Phys. D Appl. Phys."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1007\/s11770-010-0234-4","article-title":"Influences of gas bubble and ice density on ice thickness measurement by GPR","volume":"7","author":"Li","year":"2010","journal-title":"Appl. Geophys."},{"key":"ref_55","first-page":"50","article-title":"Microwave permittivity of dry snow","volume":"48","year":"1986","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"1329","DOI":"10.1109\/TAP.1986.1143757","article-title":"Dielectric properties of snow in the 3- to 37-GHz range","volume":"34","author":"Hallikainen","year":"1986","journal-title":"IEEE Trans. Antennas Propagat."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1109\/JOE.1984.1145645","article-title":"The complex dielectric constant of snow at microwave frequencies","volume":"9","author":"Tiuri","year":"1984","journal-title":"IEEE J. Ocean. Eng."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"572","DOI":"10.1364\/AO.24.000572","article-title":"Refractive index of snow at microwave frequencies","volume":"24","author":"Sadiku","year":"1985","journal-title":"Appl. Optics"},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"119","DOI":"10.2528\/PIER99020205","article-title":"Effective Permittivity of Dry Snow in the 18 to 90 GHz Range","volume":"24","author":"Huining","year":"1999","journal-title":"Prog. Electromagn. Res."},{"key":"ref_60","doi-asserted-by":"crossref","unstructured":"Rees, W.G. (2013). Physical Principles of Remote Sensing, Cambridge University Press.","DOI":"10.1017\/CBO9781139017411"},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"371","DOI":"10.5194\/tc-10-371-2016","article-title":"Intercomparison of snow density measurements: Bias, precision, and vertical resolution","volume":"10","author":"Proksch","year":"2016","journal-title":"Cryosphere"},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"1495","DOI":"10.5194\/tc-10-1495-2016","article-title":"Design of a scanning laser meter for monitoring the spatio-temporal evolution of snow depth and its application in the Alps and in Antarctica","volume":"10","author":"Picard","year":"2016","journal-title":"Cryosphere"},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"1105","DOI":"10.5194\/tc-8-1105-2014","article-title":"Influence of meter-scale wind-formed features on the variability of the microwave brightness temperature around Dome C in Antarctica","volume":"8","author":"Picard","year":"2014","journal-title":"Cryosphere"},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"1215","DOI":"10.5194\/tc-13-1215-2019","article-title":"Marked decrease of the near surface snow density retrieved by AMSR-E satellite at Dome C, Antarctica, between 2002 and 2011","volume":"13","author":"Champollion","year":"2019","journal-title":"Cryosphere"},{"key":"ref_65","unstructured":"Campbell Scientific Canada (2020, June 01). CS725 Snow Water Equivalent Sensor. Available online: https:\/\/www.campbellsci.ca\/cs725."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"2506","DOI":"10.1109\/TGRS.2008.918648","article-title":"From glacier facies to SAR backscatter zones via GPR","volume":"46","author":"Langley","year":"2008","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"2763","DOI":"10.5194\/gmd-11-2763-2018","article-title":"SMRT: An active\/passive microwave radiative transfer model for snow with multiple microstructure and scattering formulations (v1.0)","volume":"11","author":"Picard","year":"2018","journal-title":"Geosci. Model Dev."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"1836","DOI":"10.1109\/TGRS.2004.831888","article-title":"The Complex Dielectric Constant of Pure and Sea Water from Microwave Satellite Observations","volume":"42","author":"Meissner","year":"2004","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"263","DOI":"10.2528\/PIERB08081902","article-title":"Analytical formulae for radar cross section of flat plates in near field and normal incidence","volume":"9","author":"Pouliguen","year":"2008","journal-title":"Prog. Electromagn. Res."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/14\/3909\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:51:14Z","timestamp":1760176274000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/14\/3909"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,7,14]]},"references-count":69,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2020,7]]}},"alternative-id":["s20143909"],"URL":"https:\/\/doi.org\/10.3390\/s20143909","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,7,14]]}}}