{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,11]],"date-time":"2026-03-11T17:10:57Z","timestamp":1773249057143,"version":"3.50.1"},"reference-count":37,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2017,12,27]],"date-time":"2017-12-27T00:00:00Z","timestamp":1514332800000},"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>Englacial layering reflects ice dynamics within the ice bodies, which improves understanding of ice flow variation, past accumulation rates and vertical flows transferring between the surface and the underlying bedrock. The internal layers can be observed by using Radar Echo Sounding (RES), such as the Multi-channel Coherent Radar Depth Sounder (MCoRDS) used in NASA\u2019s Operation IceBridge (OIB) mission. Since the 1960s, the accumulation of the RES data has prompted the development of automated methods to extract the englacial layers. In this study, we propose a new automated method that combines peak detection methods, namely the CWT-based peak detection or the Automatic Phase Picker (APP), with a Hough Transform (HT) to trace boundaries of englacial layers. For CWT-based peak detection, we test it using two different wavelets. The proposed method is tested with twelve MCoRDS radio echograms, which are acquired south of the Northern Greenland Eemian (NEEM) ice drilling site, where the folding of ice layers was observed. The method is evaluated in comparison to the isochrones that were extracted in an independent study. In comparison, the proposed new automated method can restore more than 70% of the englacial layers. This new automated layer-tracing method is publicly available on github.<\/jats:p>","DOI":"10.3390\/rs10010043","type":"journal-article","created":{"date-parts":[[2017,12,27]],"date-time":"2017-12-27T11:16:00Z","timestamp":1514373360000},"page":"43","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["A New Method for Automatically Tracing Englacial Layers from MCoRDS Data in NW Greenland"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1054-121X","authenticated-orcid":false,"given":"Siting","family":"Xiong","sequence":"first","affiliation":[{"name":"Imaging Group, Mullard Space Science Laboratory (MSSL), Department of Space &amp; Climate Physics, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5077-3736","authenticated-orcid":false,"given":"Jan-Peter","family":"Muller","sequence":"additional","affiliation":[{"name":"Imaging Group, Mullard Space Science Laboratory (MSSL), Department of Space &amp; Climate Physics, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2233-7635","authenticated-orcid":false,"given":"Raquel","family":"Carretero","sequence":"additional","affiliation":[{"name":"Imaging Group, Mullard Space Science Laboratory (MSSL), Department of Space &amp; Climate Physics, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT, UK"},{"name":"Comillas Pontifical University of Madrid, ICAI School of Engineering, Calle Alberto Aguilera, 25, 28015 Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2017,12,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1017\/S0032247400018271","article-title":"Antarctic airborne radio echo sounding, 1977\u201378","volume":"19","author":"Drewry","year":"1978","journal-title":"Polar Rec."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"326","DOI":"10.3189\/172756404781814519","article-title":"Reconstructing ice-sheet accumulation rates at ridge B, East Antarctica","volume":"39","author":"Vieli","year":"2004","journal-title":"Ann. Glaciol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"155","DOI":"10.3189\/2015AoG70A203","article-title":"Antarctic firn-compaction rates from repeat-track airborne radar data: I. Methods","volume":"56","author":"Medley","year":"2015","journal-title":"Ann. Glaciol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1029\/2006GL026648","article-title":"Switch-off of a major enhanced ice flow unit in East Antarctica","volume":"33","author":"Rippin","year":"2006","journal-title":"Geophys. Res. Lett."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"655","DOI":"10.1002\/2014JF003291","article-title":"Ice-flow structure and ice dynamic changes in the Weddell Sea Sector of West Antarctica from radar-imaged internal layers","volume":"120","author":"Bingham","year":"2014","journal-title":"J. Geophys. Res. Earth Surf."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"195","DOI":"10.5194\/tc-3-195-2009","article-title":"Layer disturbances and the radio-echo free zone in ice sheets","volume":"3","author":"Drews","year":"2009","journal-title":"Cryosphere"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1065","DOI":"10.1002\/2015JF003698","article-title":"Overturned folds in ice sheets: Insights from a kinematic model of traveling sticky patches and comparisons with observations","volume":"121","author":"Wolovick","year":"2016","journal-title":"J. Geophys. Res. Earth Surf."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"375","DOI":"10.5194\/tc-7-375-2013","article-title":"Bedmap2: Improved ice bed, surface and thickness datasets for Antarctica","volume":"7","author":"Fretwell","year":"2013","journal-title":"Cryosphere"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"499","DOI":"10.5194\/tc-7-499-2013","article-title":"A new bed elevation dataset for Greenland","volume":"7","author":"Bamber","year":"2013","journal-title":"Cryosphere"},{"key":"ref_10","unstructured":"Wu, C., Zhang, X., Shi, J., and Liu, S. (2014, January 13\u201318). Radar signal simulation on investigation of subsurface structure by radar ice depth sounder. Proceedings of the 2014 IEEE Geoscience and Remote Sensing Symposium, Quebec City, QC, Canada."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"3791","DOI":"10.1109\/TGRS.2011.2132802","article-title":"Ice Sheet Bed Mapping with Airborne SAR Tomography","volume":"49","author":"Wu","year":"2011","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Shi, L., Allen, C.T., Ledford, J.R., Rodriguez-Morales, F., Blake, W.A., Panzer, B.G., Prokopiack, S.C., Leuschen, C.J., and Gogineni, S. (2010, January 25\u201330). Multichannel Coherent Radar Depth Sounder for NASA Operation Ice Bridge. Proceedings of the 2010 IEEE International Geoscience and Remote Sensing Symposium, Honolulu, HI, USA.","DOI":"10.1109\/IGARSS.2010.5649518"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"260","DOI":"10.3189\/002214311796405870","article-title":"Automated processing to derive dip angles of englacial radar reflectors in ice sheets","volume":"57","author":"Sime","year":"2011","journal-title":"J. Glaciol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"71","DOI":"10.3189\/2014AoG67A048","article-title":"Automated mapping of local layer slope and tracing of internal layers in radio echograms","volume":"55","author":"Panton","year":"2014","journal-title":"Ann. Glaciol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"5561","DOI":"10.1002\/2017GL073417","article-title":"Decoding ice sheet behavior using englacial layer slopes","volume":"44","author":"Holschuh","year":"2017","journal-title":"Geophys. Res. Lett."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"212","DOI":"10.1002\/2014JF003215","article-title":"Radiostratigraphy and age structure of the Greenland Ice Sheet","volume":"120","author":"MacGregor","year":"2015","journal-title":"J. Geophys. Res. Earth Surf."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1109\/TGRS.2014.2318208","article-title":"A Semiautomated Multilayer Picking Algorithm for Ice-Sheet Radar Echograms Applied to Ground-Based Near-Surface Data","volume":"53","author":"Onana","year":"2015","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_18","first-page":"585","article-title":"Extraction of englacial layers from two intersected radar echograms near NEEM ice core in Greenland","volume":"41","author":"Xiong","year":"2016","journal-title":"Int. Arch. Photogramm. Remote Sens. Spat. Inf. Sci. ISPRS"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"33789","DOI":"10.1029\/2001JD900200","article-title":"Internal layer tracing and age-depth-accumulation relationships for the northern Greenland ice sheet","volume":"106","author":"Fahnestock","year":"2011","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"11427","DOI":"10.1038\/ncomms11427","article-title":"Converging flow and anisotropy cause large-scale folding in Greenland\u2019s ice sheet","volume":"7","author":"Bons","year":"2016","journal-title":"Nat. Commun."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"323","DOI":"10.1016\/j.epsl.2015.10.024","article-title":"Automated mapping of near bed radio-echo layer disruptions in the Greenland Ice Sheet","volume":"432","author":"Panton","year":"2015","journal-title":"Earth Planet. Sci. Lett."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"489","DOI":"10.1038\/nature11789","article-title":"Eemian interglacial reconstructed from a Greenland folded ice core","volume":"493","author":"Albert","year":"2013","journal-title":"Nature"},{"key":"ref_23","unstructured":"Morlighem, M. (2015). IceBridge BedMachine Greenland, NASA DAAC at the National Snow and Ice Data Center. version 2."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"418","DOI":"10.1038\/ngeo2167","article-title":"Deeply incised submarine glacial valleys beneath the Greenland ice sheet","volume":"7","author":"Morlighem","year":"2014","journal-title":"Nat. Geosci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"5669","DOI":"10.1109\/TAP.2012.2211327","article-title":"Measurements of In-Flight Cross-Track Antenna Patterns of Radar Depth Sounder\/Imager","volume":"60","author":"Yan","year":"2012","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_26","unstructured":"Leuschen, C. (2011). IceBridge MCoRDS L1B Geolocated Radar Echo Strength Profiles, National Snow and Ice Data Center. version 1."},{"key":"ref_27","unstructured":"Leuschen, C., Gogineni, P., Hale, R., Paden, J., Rodriguez, F., Panzer, B., and Gomez, D. (2014). IceBridge MCoRDS L1B Geolocated Radar Echo Strength Profiles, National Snow and Ice Data Center. version 2."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"MacGregor, J.A., Fahnestock, M., Catania, G., Paden, J., Gogineni, P., Young, S.K., Rybarski, S.C., Mabrey, A.N., Wagman, B.M., and Morlighem, M. (2015). Radiostratigraphy and Age Structure of the Greenland Ice Sheet, NASA National Snow and Ice Data Center Distributed Active Archive Center. version 1.","DOI":"10.1002\/2014JF003215"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2059","DOI":"10.1093\/bioinformatics\/btl355","article-title":"Improved peak detection in mass spectrum by incorporating continuous wavelet transform-based pattern matching","volume":"22","author":"Du","year":"2006","journal-title":"Bioinformatics"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1016\/j.aeolia.2017.09.005","article-title":"Signal-adapted tomography as a tool for dust devil detection","volume":"29","author":"Aguirre","year":"2017","journal-title":"Aeolian Res."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1145\/361237.361242","article-title":"Use of the Hough Transformation to Detect Lines and Curves in Pictures","volume":"15","author":"Duda","year":"1972","journal-title":"Commun. ACM"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/0031-3203(81)90009-1","article-title":"Generalizing the Hough transform to detect arbitrary shapes","volume":"13","author":"Ballard","year":"1981","journal-title":"Pattern Recogn."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Grossmann, A., Kronland-Martinet, R., and Morlet, J. (1990). Reading and understanding continuous wavelet transforms. Wavelets, Springer.","DOI":"10.1007\/978-3-642-75988-8_1"},{"key":"ref_34","first-page":"1159","article-title":"Automated determination of P-phase arrival times at regional and local distances using higher order statistics","volume":"181","author":"Meier","year":"2010","journal-title":"Geophys. J. Int."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"S225","DOI":"10.1785\/BSSA07206B0225","article-title":"Automatic phase pickers: Their present use and future prospects","volume":"72","author":"Allen","year":"1982","journal-title":"Bull. Seismol. Soc. Am."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1395","DOI":"10.1109\/TGRS.2002.800438","article-title":"PAI-S\/K: A robust automatic seismic P phase arrival identification scheme","volume":"40","author":"Saragiotis","year":"2002","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1437","DOI":"10.1785\/BSSA0770041437","article-title":"An automatic phase picker for local and teleseismic events","volume":"77","author":"Baer","year":"1987","journal-title":"Bull. Seismol. Soc. Am."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/10\/1\/43\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:55:42Z","timestamp":1760208942000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/10\/1\/43"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,12,27]]},"references-count":37,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2018,1]]}},"alternative-id":["rs10010043"],"URL":"https:\/\/doi.org\/10.3390\/rs10010043","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,12,27]]}}}