{"id":"https://openalex.org/W2135873867","doi":"https://doi.org/10.1109/tgrs.2009.2017738","title":"A Hybrid Conditional Random Field for Estimating the Underlying Ground Surface From Airborne LiDAR Data","display_name":"A Hybrid Conditional Random Field for Estimating the Underlying Ground Surface From Airborne LiDAR Data","publication_year":2009,"publication_date":"2009-07-18","ids":{"openalex":"https://openalex.org/W2135873867","doi":"https://doi.org/10.1109/tgrs.2009.2017738","mag":"2135873867"},"language":"en","primary_location":{"id":"doi:10.1109/tgrs.2009.2017738","is_oa":false,"landing_page_url":"https://doi.org/10.1109/tgrs.2009.2017738","pdf_url":null,"source":{"id":"https://openalex.org/S111326731","display_name":"IEEE Transactions on Geoscience and Remote Sensing","issn_l":"0196-2892","issn":["0196-2892","1558-0644"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310319808","host_organization_name":"Institute of Electrical and Electronics Engineers","host_organization_lineage":["https://openalex.org/P4310319808"],"host_organization_lineage_names":["Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Transactions on Geoscience and Remote Sensing","raw_type":"journal-article"},"type":"article","indexed_in":["crossref"],"open_access":{"is_oa":false,"oa_status":"closed","oa_url":null,"any_repository_has_fulltext":false},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5034542716","display_name":"Wei-Lwun Lu","orcid":null},"institutions":[{"id":"https://openalex.org/I141945490","display_name":"University of British Columbia","ror":"https://ror.org/03rmrcq20","country_code":"CA","type":"education","lineage":["https://openalex.org/I141945490"]}],"countries":["CA"],"is_corresponding":true,"raw_author_name":"Wei-Lwun Lu","raw_affiliation_strings":["Department of Computer Science, University of British Columbia, Vancouver, BC, Canada","Department of Computer Science, University of British Columbia, Vancouver, BC Canada"],"affiliations":[{"raw_affiliation_string":"Department of Computer Science, University of British Columbia, Vancouver, BC, Canada","institution_ids":["https://openalex.org/I141945490"]},{"raw_affiliation_string":"Department of Computer Science, University of British Columbia, Vancouver, BC Canada","institution_ids":["https://openalex.org/I141945490"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5103362817","display_name":"Kevin P. Murphy","orcid":null},"institutions":[{"id":"https://openalex.org/I141945490","display_name":"University of British Columbia","ror":"https://ror.org/03rmrcq20","country_code":"CA","type":"education","lineage":["https://openalex.org/I141945490"]}],"countries":["CA"],"is_corresponding":false,"raw_author_name":"K.P. Murphy","raw_affiliation_strings":["Department of Computer Science, University of British Columbia, Vancouver, BC, Canada","Department of Computer Science, University of British Columbia, Vancouver, BC Canada"],"affiliations":[{"raw_affiliation_string":"Department of Computer Science, University of British Columbia, Vancouver, BC, Canada","institution_ids":["https://openalex.org/I141945490"]},{"raw_affiliation_string":"Department of Computer Science, University of British Columbia, Vancouver, BC Canada","institution_ids":["https://openalex.org/I141945490"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5102754179","display_name":"James J. Little","orcid":"https://orcid.org/0000-0002-4411-2544"},"institutions":[{"id":"https://openalex.org/I141945490","display_name":"University of British Columbia","ror":"https://ror.org/03rmrcq20","country_code":"CA","type":"education","lineage":["https://openalex.org/I141945490"]}],"countries":["CA"],"is_corresponding":false,"raw_author_name":"J.J. Little","raw_affiliation_strings":["Department of Computer Science, University of British Columbia, Vancouver, BC, Canada","Department of Computer Science, University of British Columbia, Vancouver, BC Canada"],"affiliations":[{"raw_affiliation_string":"Department of Computer Science, University of British Columbia, Vancouver, BC, Canada","institution_ids":["https://openalex.org/I141945490"]},{"raw_affiliation_string":"Department of Computer Science, University of British Columbia, Vancouver, BC Canada","institution_ids":["https://openalex.org/I141945490"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5053259123","display_name":"Alla Sheffer","orcid":"https://orcid.org/0000-0001-9251-3716"},"institutions":[{"id":"https://openalex.org/I141945490","display_name":"University of British Columbia","ror":"https://ror.org/03rmrcq20","country_code":"CA","type":"education","lineage":["https://openalex.org/I141945490"]}],"countries":["CA"],"is_corresponding":false,"raw_author_name":"A. Sheffer","raw_affiliation_strings":["Department of Computer Science, University of British Columbia, Vancouver, BC, Canada","Department of Computer Science, University of British Columbia, Vancouver, BC Canada"],"affiliations":[{"raw_affiliation_string":"Department of Computer Science, University of British Columbia, Vancouver, BC, Canada","institution_ids":["https://openalex.org/I141945490"]},{"raw_affiliation_string":"Department of Computer Science, University of British Columbia, Vancouver, BC Canada","institution_ids":["https://openalex.org/I141945490"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5100616579","display_name":"Hongbo Fu","orcid":"https://orcid.org/0000-0002-0284-726X"},"institutions":[{"id":"https://openalex.org/I168719708","display_name":"City University of Hong Kong","ror":"https://ror.org/03q8dnn23","country_code":"HK","type":"education","lineage":["https://openalex.org/I168719708"]}],"countries":["HK"],"is_corresponding":false,"raw_author_name":"Hongbo Fu","raw_affiliation_strings":["School of Creative Media, City University of Hong Kong, Hong Kong, China","School of Creative Media"],"affiliations":[{"raw_affiliation_string":"School of Creative Media, City University of Hong Kong, Hong Kong, China","institution_ids":["https://openalex.org/I168719708"]},{"raw_affiliation_string":"School of Creative Media","institution_ids":[]}]}],"institutions":[],"countries_distinct_count":2,"institutions_distinct_count":5,"corresponding_author_ids":["https://openalex.org/A5034542716"],"corresponding_institution_ids":["https://openalex.org/I141945490"],"apc_list":null,"apc_paid":null,"fwci":4.0659,"has_fulltext":false,"cited_by_count":70,"citation_normalized_percentile":{"value":0.932053,"is_in_top_1_percent":false,"is_in_top_10_percent":true},"cited_by_percentile_year":{"min":94,"max":99},"biblio":{"volume":"47","issue":"8","first_page":"2913","last_page":"2922"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11164","display_name":"Remote Sensing and LiDAR Applications","score":1.0,"subfield":{"id":"https://openalex.org/subfields/2305","display_name":"Environmental Engineering"},"field":{"id":"https://openalex.org/fields/23","display_name":"Environmental Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T11164","display_name":"Remote Sensing and LiDAR Applications","score":1.0,"subfield":{"id":"https://openalex.org/subfields/2305","display_name":"Environmental Engineering"},"field":{"id":"https://openalex.org/fields/23","display_name":"Environmental Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T10111","display_name":"Remote Sensing in Agriculture","score":0.9962000250816345,"subfield":{"id":"https://openalex.org/subfields/2303","display_name":"Ecology"},"field":{"id":"https://openalex.org/fields/23","display_name":"Environmental Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T11211","display_name":"3D Surveying and Cultural Heritage","score":0.9952999949455261,"subfield":{"id":"https://openalex.org/subfields/1907","display_name":"Geology"},"field":{"id":"https://openalex.org/fields/19","display_name":"Earth and Planetary Sciences"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/lidar","display_name":"Lidar","score":0.617053210735321},{"id":"https://openalex.org/keywords/artificial-intelligence","display_name":"Artificial intelligence","score":0.5951368808746338},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.5801237225532532},{"id":"https://openalex.org/keywords/terrain","display_name":"Terrain","score":0.5341381430625916},{"id":"https://openalex.org/keywords/discriminative-model","display_name":"Discriminative model","score":0.495036780834198},{"id":"https://openalex.org/keywords/point-cloud","display_name":"Point cloud","score":0.4830656349658966},{"id":"https://openalex.org/keywords/field","display_name":"Field (mathematics)","score":0.4455667734146118},{"id":"https://openalex.org/keywords/remote-sensing","display_name":"Remote sensing","score":0.44536086916923523},{"id":"https://openalex.org/keywords/conditional-random-field","display_name":"Conditional random field","score":0.43344345688819885},{"id":"https://openalex.org/keywords/machine-learning","display_name":"Machine learning","score":0.3962121307849884},{"id":"https://openalex.org/keywords/algorithm","display_name":"Algorithm","score":0.34080201387405396},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.22263029217720032},{"id":"https://openalex.org/keywords/geology","display_name":"Geology","score":0.15403583645820618},{"id":"https://openalex.org/keywords/cartography","display_name":"Cartography","score":0.11972859501838684},{"id":"https://openalex.org/keywords/geography","display_name":"Geography","score":0.10802590847015381}],"concepts":[{"id":"https://openalex.org/C51399673","wikidata":"https://www.wikidata.org/wiki/Q504027","display_name":"Lidar","level":2,"score":0.617053210735321},{"id":"https://openalex.org/C154945302","wikidata":"https://www.wikidata.org/wiki/Q11660","display_name":"Artificial intelligence","level":1,"score":0.5951368808746338},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.5801237225532532},{"id":"https://openalex.org/C161840515","wikidata":"https://www.wikidata.org/wiki/Q186131","display_name":"Terrain","level":2,"score":0.5341381430625916},{"id":"https://openalex.org/C97931131","wikidata":"https://www.wikidata.org/wiki/Q5282087","display_name":"Discriminative model","level":2,"score":0.495036780834198},{"id":"https://openalex.org/C131979681","wikidata":"https://www.wikidata.org/wiki/Q1899648","display_name":"Point cloud","level":2,"score":0.4830656349658966},{"id":"https://openalex.org/C9652623","wikidata":"https://www.wikidata.org/wiki/Q190109","display_name":"Field (mathematics)","level":2,"score":0.4455667734146118},{"id":"https://openalex.org/C62649853","wikidata":"https://www.wikidata.org/wiki/Q199687","display_name":"Remote sensing","level":1,"score":0.44536086916923523},{"id":"https://openalex.org/C152565575","wikidata":"https://www.wikidata.org/wiki/Q1124538","display_name":"Conditional random field","level":2,"score":0.43344345688819885},{"id":"https://openalex.org/C119857082","wikidata":"https://www.wikidata.org/wiki/Q2539","display_name":"Machine learning","level":1,"score":0.3962121307849884},{"id":"https://openalex.org/C11413529","wikidata":"https://www.wikidata.org/wiki/Q8366","display_name":"Algorithm","level":1,"score":0.34080201387405396},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.22263029217720032},{"id":"https://openalex.org/C127313418","wikidata":"https://www.wikidata.org/wiki/Q1069","display_name":"Geology","level":0,"score":0.15403583645820618},{"id":"https://openalex.org/C58640448","wikidata":"https://www.wikidata.org/wiki/Q42515","display_name":"Cartography","level":1,"score":0.11972859501838684},{"id":"https://openalex.org/C205649164","wikidata":"https://www.wikidata.org/wiki/Q1071","display_name":"Geography","level":0,"score":0.10802590847015381},{"id":"https://openalex.org/C202444582","wikidata":"https://www.wikidata.org/wiki/Q837863","display_name":"Pure mathematics","level":1,"score":0.0}],"mesh":[],"locations_count":2,"locations":[{"id":"doi:10.1109/tgrs.2009.2017738","is_oa":false,"landing_page_url":"https://doi.org/10.1109/tgrs.2009.2017738","pdf_url":null,"source":{"id":"https://openalex.org/S111326731","display_name":"IEEE Transactions on Geoscience and Remote Sensing","issn_l":"0196-2892","issn":["0196-2892","1558-0644"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310319808","host_organization_name":"Institute of Electrical and Electronics Engineers","host_organization_lineage":["https://openalex.org/P4310319808"],"host_organization_lineage_names":["Institute of Electrical and Electronics Engineers"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"IEEE Transactions on Geoscience and Remote Sensing","raw_type":"journal-article"},{"id":"pmh:oai:repository.hkust.edu.hk:1783.1-138299","is_oa":false,"landing_page_url":"http://gateway.isiknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=LinksAMR&SrcApp=PARTNER_APP&DestLinkType=FullRecord&DestApp=WOS&KeyUT=000268167000019","pdf_url":null,"source":{"id":"https://openalex.org/S4306401796","display_name":"Rare & Special e-Zone (The Hong Kong University of Science and Technology)","issn_l":null,"issn":null,"is_oa":false,"is_in_doaj":false,"is_core":false,"host_organization":"https://openalex.org/I200769079","host_organization_name":"Hong Kong University of Science and Technology","host_organization_lineage":["https://openalex.org/I200769079"],"host_organization_lineage_names":[],"type":"repository"},"license":null,"license_id":null,"version":"submittedVersion","is_accepted":false,"is_published":false,"raw_source_name":null,"raw_type":"Article"}],"best_oa_location":null,"sustainable_development_goals":[{"display_name":"Reduced inequalities","score":0.5899999737739563,"id":"https://metadata.un.org/sdg/10"}],"awards":[],"funders":[{"id":"https://openalex.org/F4320313934","display_name":"Institut national de recherche en informatique et en automatique (INRIA)","ror":"https://ror.org/02kvxyf05"}],"has_content":{"pdf":false,"grobid_xml":false},"content_urls":null,"referenced_works_count":46,"referenced_works":["https://openalex.org/W48960425","https://openalex.org/W54516136","https://openalex.org/W59966576","https://openalex.org/W143236119","https://openalex.org/W184119462","https://openalex.org/W1549656520","https://openalex.org/W1557726990","https://openalex.org/W1601795611","https://openalex.org/W1618905105","https://openalex.org/W1663973292","https://openalex.org/W1803896282","https://openalex.org/W1990068598","https://openalex.org/W1999478155","https://openalex.org/W2006502673","https://openalex.org/W2009214675","https://openalex.org/W2024046085","https://openalex.org/W2027781877","https://openalex.org/W2052069724","https://openalex.org/W2052735510","https://openalex.org/W2056769281","https://openalex.org/W2060530519","https://openalex.org/W2093111123","https://openalex.org/W2101431297","https://openalex.org/W2104998606","https://openalex.org/W2114161509","https://openalex.org/W2114892120","https://openalex.org/W2115703234","https://openalex.org/W2119821739","https://openalex.org/W2124189704","https://openalex.org/W2131048615","https://openalex.org/W2134345313","https://openalex.org/W2147880316","https://openalex.org/W2162250508","https://openalex.org/W2170635585","https://openalex.org/W2567948266","https://openalex.org/W4229929111","https://openalex.org/W4239510810","https://openalex.org/W6601946194","https://openalex.org/W6602225176","https://openalex.org/W6602412256","https://openalex.org/W6607468067","https://openalex.org/W6633454732","https://openalex.org/W6638473115","https://openalex.org/W6663462149","https://openalex.org/W6679377883","https://openalex.org/W6682082992"],"related_works":["https://openalex.org/W2394196665","https://openalex.org/W2599951341","https://openalex.org/W2048280290","https://openalex.org/W2064376096","https://openalex.org/W1997147308","https://openalex.org/W3047022030","https://openalex.org/W2335177719","https://openalex.org/W1980262250","https://openalex.org/W51427204","https://openalex.org/W4366775409"],"abstract_inverted_index":{"Recent":[0],"advances":[1],"in":[2,35],"airborne":[3],"light":[4],"detection":[5],"and":[6,12,27,42,140,144],"ranging":[7],"(LiDAR)":[8],"technology":[9],"allow":[10],"rapid":[11],"inexpensive":[13],"generation":[14],"of":[15,23,51,92,110,182,194,204],"digital":[16,45],"surface":[17,112,184],"models":[18,47],"(DSMs),":[19],"3-D":[20],"point":[21,77],"clouds":[22],"buildings,":[24],"vegetations,":[25],"cars,":[26],"natural":[28],"terrain":[29,46],"features":[30],"over":[31],"large":[32],"regions.":[33],"However,":[34],"many":[36],"applications,":[37],"such":[38],"as":[39,78,100,107],"flood":[40],"modeling":[41],"landslide":[43],"prediction,":[44],"(DTMs),":[48],"the":[49,52,95,104,111,116,183,195,202,209],"topography":[50],"bare-Earth":[53],"surface,":[54],"are":[55,98],"needed.":[56],"This":[57],"paper":[58],"introduces":[59],"a":[60,90,130,146,156,173,192],"novel":[61],"machine":[62],"learning":[63,86],"approach":[64,207],"to":[65,89,121],"automatically":[66],"extract":[67],"DTMs":[68],"from":[69],"their":[70],"corresponding":[71],"DSMs.":[72],"We":[73,170],"first":[74],"classify":[75],"each":[76],"being":[79],"either":[80],"ground":[81],"or":[82],"nonground,":[83],"using":[84,129,191],"supervised":[85],"techniques":[87],"applied":[88],"variety":[91],"features.":[93],"For":[94],"points":[96],"which":[97,126],"classified":[99],"ground,":[101],"we":[102,119,127,153],"use":[103],"LiDAR":[105],"measurements":[106],"an":[108],"estimate":[109,181],"height,":[113],"but,":[114],"for":[115],"nonground":[117],"points,":[118],"have":[120],"interpolate":[122],"between":[123],"nearby":[124],"values,":[125],"do":[128],"Gaussian":[131],"random":[132],"field.":[133],"Since":[134],"our":[135],"model":[136],"contains":[137],"both":[138],"discrete":[139],"continuous":[141],"latent":[142],"variables,":[143],"is":[145],"discriminative":[147],"(rather":[148],"than":[149],"generative)":[150],"probabilistic":[151],"model,":[152],"call":[154],"it":[155],"<i":[157,160,163,166,175,178],"xmlns:mml=\"http://www.w3.org/1998/Math/MathML\"":[158,161,164,167,176,179],"xmlns:xlink=\"http://www.w3.org/1999/xlink\">hybrid</i>":[159],"xmlns:xlink=\"http://www.w3.org/1999/xlink\">conditional</i>":[162],"xmlns:xlink=\"http://www.w3.org/1999/xlink\">random</i>":[165],"xmlns:xlink=\"http://www.w3.org/1999/xlink\">field</i>":[168],".":[169],"show":[171],"that":[172,201],"Maximum":[174],"xmlns:xlink=\"http://www.w3.org/1999/xlink\">a</i>":[177],"xmlns:xlink=\"http://www.w3.org/1999/xlink\">Posteriori</i>":[180],"height":[185],"can":[186],"be":[187],"efficiently":[188],"estimated":[189],"by":[190],"variant":[193],"Expectation":[196],"Maximization":[197],"algorithm.":[198],"Experiments":[199],"demonstrate":[200],"accuracy":[203],"this":[205],"learning-based":[206],"outperforms":[208],"previous":[210],"best":[211],"systems,":[212],"based":[213],"on":[214],"manually":[215],"tuned":[216],"heuristics.":[217]},"counts_by_year":[{"year":2025,"cited_by_count":2},{"year":2024,"cited_by_count":2},{"year":2023,"cited_by_count":3},{"year":2022,"cited_by_count":3},{"year":2021,"cited_by_count":3},{"year":2020,"cited_by_count":2},{"year":2019,"cited_by_count":7},{"year":2018,"cited_by_count":4},{"year":2017,"cited_by_count":4},{"year":2016,"cited_by_count":6},{"year":2015,"cited_by_count":10},{"year":2014,"cited_by_count":5},{"year":2013,"cited_by_count":4},{"year":2012,"cited_by_count":7}],"updated_date":"2025-11-06T03:46:38.306776","created_date":"2025-10-10T00:00:00"}