{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,28]],"date-time":"2025-10-28T15:09:15Z","timestamp":1761664155038,"version":"build-2065373602"},"reference-count":20,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2020,11,9]],"date-time":"2020-11-09T00:00:00Z","timestamp":1604880000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Schweizerischer Nationalfonds zur F&amp;#x00F6;rderung der Wissenschaftlichen Forschung","award":["P400P2_186687"],"award-info":[{"award-number":["P400P2_186687"]}]},{"name":"Royal Society University Research Fellowship","award":["UF140021"],"award-info":[{"award-number":["UF140021"]}]},{"name":"NERC grant","award":["NE\/N009312\/1"],"award-info":[{"award-number":["NE\/N009312\/1"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Radar measurements of gravitational mass-movements like snow avalanches have become increasingly important for scientific flow observations, real-time detection and monitoring. Independence of visibility is a main advantage for rapid and reliable detection of those events, and achievable high-resolution imaging proves invaluable for scientific measurements of the complete flow evolution. Existing radar systems are made for either detection with low-resolution or they are large devices and permanently installed at test-sites. We present mGEODAR, a mobile FMCW (frequency modulated continuous wave) radar system for high-resolution measurements and low-resolution gravitational mass-movement detection and monitoring purposes due to a versatile frequency generation scheme. We optimize the performance of different frequency settings with loop cable measurements and show the freespace range sensitivity with data of a car as moving point source. About 15 dB signal-to-noise ratio is achieved for the cable test and about 5 dB or 10 dB for the car in detection and research mode, respectively. By combining continuous recording in the low resolution detection mode with real-time triggering of the high resolution research mode, we expect that mGEODAR enables autonomous measurement campaigns for infrastructure safety and mass-movement research purposes in rapid response to changing weather and snow conditions.<\/jats:p>","DOI":"10.3390\/s20216373","type":"journal-article","created":{"date-parts":[[2020,11,10]],"date-time":"2020-11-10T14:10:41Z","timestamp":1605017441000},"page":"6373","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["mGEODAR\u2014A Mobile Radar System for Detection and Monitoring of Gravitational Mass-Movements"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7431-0691","authenticated-orcid":false,"given":"Anselm","family":"K\u00f6hler","sequence":"first","affiliation":[{"name":"Department of Natural Hazards, Austrian Research Centre for Forests (BFW), 6020 Innsbruck, Austria"},{"name":"WSL-Institute for Snow and Avalanche Research SLF, 7260 Davos Dorf, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0033-9173","authenticated-orcid":false,"given":"Lai Bun","family":"Lok","sequence":"additional","affiliation":[{"name":"Department of Engineering, Lancaster University, Lancaster LA1 4YW, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Simon","family":"Felbermayr","sequence":"additional","affiliation":[{"name":"Department of Natural Hazards, Austrian Research Centre for Forests (BFW), 6020 Innsbruck, Austria"},{"name":"Department of Mechatronic, Management Centre Innsbruck (MCI), 6020 Innsbruck, Austria"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6817-6262","authenticated-orcid":false,"given":"Nial","family":"Peters","sequence":"additional","affiliation":[{"name":"Department of Electronic and Electrical Engineering, University College London, London WC1E 6BT, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3145-3868","authenticated-orcid":false,"given":"Paul V.","family":"Brennan","sequence":"additional","affiliation":[{"name":"Department of Electronic and Electrical Engineering, University College London, London WC1E 6BT, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5179-6457","authenticated-orcid":false,"given":"Jan-Thomas","family":"Fischer","sequence":"additional","affiliation":[{"name":"Department of Natural Hazards, Austrian Research Centre for Forests (BFW), 6020 Innsbruck, Austria"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,11,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"26","DOI":"10.3189\/1985AoG6-1-26-34","article-title":"Measurement and Analysis of the Motion of Dense Flow Avalanches","volume":"6","author":"Salm","year":"1985","journal-title":"Ann. Glaciol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1016\/j.coldregions.2007.03.009","article-title":"On pulsed Doppler radar measurements of avalanches and their implication to avalanche dynamics","volume":"6","author":"Gauer","year":"2007","journal-title":"Cold Reg. Sci. Tech."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Ash, M., Brennan, P.V., Chetty, K., McElwaine, J.N., and Keylock, C.J. (2010, January 10\u201314). FMCW Radar Imaging of Avalanche-like Snow Movements. Proceedings of the 2010 IEEE Radar Conference, Washington, DC, USA.","DOI":"10.1109\/RADAR.2010.5494643"},{"key":"ref_4","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_5","doi-asserted-by":"crossref","first-page":"2192","DOI":"10.1002\/2016JF003887","article-title":"The dynamics of surges in the 3 February 2015 avalanches in Vall\u00e9e de la Sionne","volume":"121","author":"McElwaine","year":"2016","journal-title":"J. Geophys. Res."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1183","DOI":"10.1002\/2018JF004665","article-title":"Looking Beyond the Powder\/Dense Flow Avalanche Dichotomy","volume":"123","author":"Faug","year":"2018","journal-title":"J. Geophys. Res."},{"key":"ref_7","unstructured":"K\u00f6hler, A., Sovilla, B., and McElwaine, J.N. (2018, January 7\u201312). 7 years of avalanche measurements with the GEODAR radar system. Proceedings of the International Snow Science Workshop, Innsbruck, Austria."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Ash, M., Tanha, M.A., Brennan, P.V., K\u00f6hler, A., McElwaine, J.N., and Keylock, C.J. (2014, January 13\u201317). Improving the sensitivity and phased array response of FMCW radar for imaging avalanches. Proceedings of the 2014 International Radar Conference, Lille, France.","DOI":"10.1109\/RADAR.2014.7060387"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1016\/j.coldregions.2014.02.004","article-title":"Two-Dimensional Radar Imaging of Flowing Avalanches","volume":"102","author":"Ash","year":"2014","journal-title":"Cold Reg. Sci. Tech."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"8897","DOI":"10.1029\/2018GL079177","article-title":"Radar Altimetry as a Robust Tool for Monitoring the Active Lava Lake at Erebus Volcano, Antarctica","volume":"45","author":"Peters","year":"2018","journal-title":"Geophys. Res. Lett."},{"key":"ref_11","unstructured":"Gentile, K. (2020, May 30). Super-Nyquist Operation of the AD9912 Yields a High RF Output Signal. Available online: http:\/\/www.analog.com\/media\/en\/technical-documentation\/application-notes\/AN-939.pdf."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1594","DOI":"10.1109\/TAES.2011.5937252","article-title":"Determination of Sweep Linearity Requirements in FMCW Radar Systems Based on Simple Voltage-Controlled Oscillator Sources","volume":"47","author":"Brennan","year":"2011","journal-title":"IEEE Trans. Aerosp. Electron. Syst."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"413","DOI":"10.1049\/el.2014.4236","article-title":"Transmitter noise considerations in super-Nyquist FMCW radar design","volume":"51","author":"Ash","year":"2015","journal-title":"IEEE Electron. Lett."},{"key":"ref_14","unstructured":"Federal Ministry for Transport, Innovation and Technology (BMVIT) (2020, September 14). Frequenznutzungsverordnung 2013, BGBl. II Nr. 63\/2014 (German). Available online: https:\/\/www.ris.bka.gv.at\/eli\/bgbl\/II\/2014\/63\/20140324."},{"key":"ref_15","unstructured":"Stove, A.G. (2004, January 11\u201315). Modern FMCW radar\u2014Techniques and applications. Proceedings of the First European Radar Conference, Amsterdam, The Netherlands."},{"key":"ref_16","unstructured":"K\u00f6hler, A. (2018). High Resolution Radar Imaging of Snow Avalanches. [Ph.D. Thesis, Durham University]."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1272","DOI":"10.1002\/2017JF004375","article-title":"GEODAR Data and the Flow Regimes of Snow Avalanches","volume":"123","author":"McElwaine","year":"2018","journal-title":"J. Geophys. Res."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"EL264","DOI":"10.1121\/1.4929619","article-title":"Uncertainty of decibel levels","volume":"138","author":"Taraldsen","year":"2015","journal-title":"J. Acoust."},{"key":"ref_19","unstructured":"Ash, M. (2013). FMCW Phased Array Radar for Imaging Snow Avalanches. [Ph.D. Thesis, University College London]."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"3576","DOI":"10.1364\/OSAC.2.003576","article-title":"Electro-optic frequency combs generated via direct digital synthesis applied to sub-Doppler spectroscopy","volume":"2","author":"Long","year":"2019","journal-title":"OSA Continuum."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/21\/6373\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T10:30:55Z","timestamp":1760178655000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/21\/6373"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,11,9]]},"references-count":20,"journal-issue":{"issue":"21","published-online":{"date-parts":[[2020,11]]}},"alternative-id":["s20216373"],"URL":"https:\/\/doi.org\/10.3390\/s20216373","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2020,11,9]]}}}