{"id":"https://openalex.org/W3194935912","doi":"https://doi.org/10.1109/lgrs.2021.3093046","title":"A GPS-IR Method for Retrieving NDVI From Integrated Dual-Frequency Observations","display_name":"A GPS-IR Method for Retrieving NDVI From Integrated Dual-Frequency Observations","publication_year":2021,"publication_date":"2021-08-24","ids":{"openalex":"https://openalex.org/W3194935912","doi":"https://doi.org/10.1109/lgrs.2021.3093046","mag":"3194935912"},"language":"en","primary_location":{"id":"doi:10.1109/lgrs.2021.3093046","is_oa":false,"landing_page_url":"https://doi.org/10.1109/lgrs.2021.3093046","pdf_url":null,"source":{"id":"https://openalex.org/S126920919","display_name":"IEEE Geoscience and Remote Sensing Letters","issn_l":"1545-598X","issn":["1545-598X","1558-0571"],"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 Geoscience and Remote Sensing Letters","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/A5061618847","display_name":"Jichao Lv","orcid":"https://orcid.org/0000-0003-2082-945X"},"institutions":[{"id":"https://openalex.org/I4800084","display_name":"Southwest Jiaotong University","ror":"https://ror.org/00hn7w693","country_code":"CN","type":"education","lineage":["https://openalex.org/I4800084"]}],"countries":["CN"],"is_corresponding":true,"raw_author_name":"Jichao Lv","raw_affiliation_strings":["Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China"],"raw_orcid":"https://orcid.org/0000-0003-2082-945X","affiliations":[{"raw_affiliation_string":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China","institution_ids":["https://openalex.org/I4800084"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5039949921","display_name":"Rui Zhang","orcid":"https://orcid.org/0000-0002-0809-7682"},"institutions":[{"id":"https://openalex.org/I4800084","display_name":"Southwest Jiaotong University","ror":"https://ror.org/00hn7w693","country_code":"CN","type":"education","lineage":["https://openalex.org/I4800084"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Rui Zhang","raw_affiliation_strings":["Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China"],"raw_orcid":"https://orcid.org/0000-0002-0809-7682","affiliations":[{"raw_affiliation_string":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China","institution_ids":["https://openalex.org/I4800084"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5100644224","display_name":"Bin Yu","orcid":"https://orcid.org/0000-0003-2683-2262"},"institutions":[{"id":"https://openalex.org/I4800084","display_name":"Southwest Jiaotong University","ror":"https://ror.org/00hn7w693","country_code":"CN","type":"education","lineage":["https://openalex.org/I4800084"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Bin Yu","raw_affiliation_strings":["Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China","institution_ids":["https://openalex.org/I4800084"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5089851529","display_name":"Jiatai Pang","orcid":null},"institutions":[{"id":"https://openalex.org/I4800084","display_name":"Southwest Jiaotong University","ror":"https://ror.org/00hn7w693","country_code":"CN","type":"education","lineage":["https://openalex.org/I4800084"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Jiatai Pang","raw_affiliation_strings":["Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China","institution_ids":["https://openalex.org/I4800084"]}]},{"author_position":"middle","author":{"id":"https://openalex.org/A5014981555","display_name":"Mingjie Liao","orcid":"https://orcid.org/0000-0001-8903-3535"},"institutions":[{"id":"https://openalex.org/I4800084","display_name":"Southwest Jiaotong University","ror":"https://ror.org/00hn7w693","country_code":"CN","type":"education","lineage":["https://openalex.org/I4800084"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Mingjie Liao","raw_affiliation_strings":["Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China"],"raw_orcid":null,"affiliations":[{"raw_affiliation_string":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China","institution_ids":["https://openalex.org/I4800084"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5101656253","display_name":"Guoxiang Liu","orcid":"https://orcid.org/0000-0002-2799-1145"},"institutions":[{"id":"https://openalex.org/I4800084","display_name":"Southwest Jiaotong University","ror":"https://ror.org/00hn7w693","country_code":"CN","type":"education","lineage":["https://openalex.org/I4800084"]}],"countries":["CN"],"is_corresponding":false,"raw_author_name":"Guoxiang Liu","raw_affiliation_strings":["Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China"],"raw_orcid":"https://orcid.org/0000-0002-2799-1145","affiliations":[{"raw_affiliation_string":"Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu, China","institution_ids":["https://openalex.org/I4800084"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":6,"corresponding_author_ids":["https://openalex.org/A5061618847"],"corresponding_institution_ids":["https://openalex.org/I4800084"],"apc_list":null,"apc_paid":null,"fwci":0.3659,"has_fulltext":false,"cited_by_count":6,"citation_normalized_percentile":{"value":0.5606585,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":94,"max":96},"biblio":{"volume":"19","issue":null,"first_page":"1","last_page":"5"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T11312","display_name":"Soil Moisture and Remote Sensing","score":0.9995999932289124,"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/T11312","display_name":"Soil Moisture and Remote Sensing","score":0.9995999932289124,"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/T10770","display_name":"Soil Geostatistics and Mapping","score":0.9979000091552734,"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/T11164","display_name":"Remote Sensing and LiDAR Applications","score":0.9966999888420105,"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"}}],"keywords":[{"id":"https://openalex.org/keywords/normalized-difference-vegetation-index","display_name":"Normalized Difference Vegetation Index","score":0.8057913780212402},{"id":"https://openalex.org/keywords/remote-sensing","display_name":"Remote sensing","score":0.6652237176895142},{"id":"https://openalex.org/keywords/global-positioning-system","display_name":"Global Positioning System","score":0.5771756172180176},{"id":"https://openalex.org/keywords/mean-squared-error","display_name":"Mean squared error","score":0.5219763517379761},{"id":"https://openalex.org/keywords/correlation-coefficient","display_name":"Correlation coefficient","score":0.4223945736885071},{"id":"https://openalex.org/keywords/computer-science","display_name":"Computer science","score":0.3868265748023987},{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.2746339738368988},{"id":"https://openalex.org/keywords/statistics","display_name":"Statistics","score":0.18653950095176697},{"id":"https://openalex.org/keywords/geology","display_name":"Geology","score":0.12729886174201965}],"concepts":[{"id":"https://openalex.org/C1549246","wikidata":"https://www.wikidata.org/wiki/Q718775","display_name":"Normalized Difference Vegetation Index","level":3,"score":0.8057913780212402},{"id":"https://openalex.org/C62649853","wikidata":"https://www.wikidata.org/wiki/Q199687","display_name":"Remote sensing","level":1,"score":0.6652237176895142},{"id":"https://openalex.org/C60229501","wikidata":"https://www.wikidata.org/wiki/Q18822","display_name":"Global Positioning System","level":2,"score":0.5771756172180176},{"id":"https://openalex.org/C139945424","wikidata":"https://www.wikidata.org/wiki/Q1940696","display_name":"Mean squared error","level":2,"score":0.5219763517379761},{"id":"https://openalex.org/C2780092901","wikidata":"https://www.wikidata.org/wiki/Q3433612","display_name":"Correlation coefficient","level":2,"score":0.4223945736885071},{"id":"https://openalex.org/C41008148","wikidata":"https://www.wikidata.org/wiki/Q21198","display_name":"Computer science","level":0,"score":0.3868265748023987},{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.2746339738368988},{"id":"https://openalex.org/C105795698","wikidata":"https://www.wikidata.org/wiki/Q12483","display_name":"Statistics","level":1,"score":0.18653950095176697},{"id":"https://openalex.org/C127313418","wikidata":"https://www.wikidata.org/wiki/Q1069","display_name":"Geology","level":0,"score":0.12729886174201965},{"id":"https://openalex.org/C132651083","wikidata":"https://www.wikidata.org/wiki/Q7942","display_name":"Climate change","level":2,"score":0.0},{"id":"https://openalex.org/C111368507","wikidata":"https://www.wikidata.org/wiki/Q43518","display_name":"Oceanography","level":1,"score":0.0},{"id":"https://openalex.org/C76155785","wikidata":"https://www.wikidata.org/wiki/Q418","display_name":"Telecommunications","level":1,"score":0.0}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.1109/lgrs.2021.3093046","is_oa":false,"landing_page_url":"https://doi.org/10.1109/lgrs.2021.3093046","pdf_url":null,"source":{"id":"https://openalex.org/S126920919","display_name":"IEEE Geoscience and Remote Sensing Letters","issn_l":"1545-598X","issn":["1545-598X","1558-0571"],"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 Geoscience and Remote Sensing Letters","raw_type":"journal-article"}],"best_oa_location":null,"sustainable_development_goals":[{"score":0.5799999833106995,"id":"https://metadata.un.org/sdg/15","display_name":"Life in Land"}],"awards":[{"id":"https://openalex.org/G1266425772","display_name":null,"funder_award_id":"2017YFB0502700","funder_id":"https://openalex.org/F4320335777","funder_display_name":"National Key Research and Development Program of China"},{"id":"https://openalex.org/G1624205435","display_name":null,"funder_award_id":"2020YJ0322","funder_id":"https://openalex.org/F4320333335","funder_display_name":"Sichuan Province Science and Technology Support Program"},{"id":"https://openalex.org/G1720704566","display_name":null,"funder_award_id":"2020JDTD0003","funder_id":"https://openalex.org/F4320333335","funder_display_name":"Sichuan Province Science and Technology Support Program"},{"id":"https://openalex.org/G4035461853","display_name":null,"funder_award_id":"41771402","funder_id":"https://openalex.org/F4320321001","funder_display_name":"National Natural Science Foundation of China"},{"id":"https://openalex.org/G4502791344","display_name":null,"funder_award_id":"2018JY0664","funder_id":"https://openalex.org/F4320333335","funder_display_name":"Sichuan Province Science and Technology Support Program"},{"id":"https://openalex.org/G8713683287","display_name":null,"funder_award_id":"2019ZDZX0042","funder_id":"https://openalex.org/F4320333335","funder_display_name":"Sichuan Province Science and Technology Support Program"}],"funders":[{"id":"https://openalex.org/F4320321001","display_name":"National Natural Science Foundation of China","ror":"https://ror.org/01h0zpd94"},{"id":"https://openalex.org/F4320333335","display_name":"Sichuan Province Science and Technology Support Program","ror":null},{"id":"https://openalex.org/F4320335777","display_name":"National Key Research and Development Program of China","ror":null}],"has_content":{"grobid_xml":false,"pdf":false},"content_urls":null,"referenced_works_count":17,"referenced_works":["https://openalex.org/W799363603","https://openalex.org/W1658490829","https://openalex.org/W1971263100","https://openalex.org/W1977531189","https://openalex.org/W1984127772","https://openalex.org/W2028099599","https://openalex.org/W2100335098","https://openalex.org/W2126250722","https://openalex.org/W2128235407","https://openalex.org/W2132083787","https://openalex.org/W2150903529","https://openalex.org/W2159223272","https://openalex.org/W2160496639","https://openalex.org/W2167968759","https://openalex.org/W2464649467","https://openalex.org/W3014764067","https://openalex.org/W6775859859"],"related_works":["https://openalex.org/W2474967816","https://openalex.org/W3080244183","https://openalex.org/W2363209489","https://openalex.org/W3153926312","https://openalex.org/W3090216389","https://openalex.org/W3092263277","https://openalex.org/W2186116122","https://openalex.org/W2383879320","https://openalex.org/W2990383350","https://openalex.org/W1992287538"],"abstract_inverted_index":{"The":[0,49,158,220],"global":[1],"positioning":[2],"system":[3],"interferometric":[4],"reflectometry":[5],"(GPS-IR)":[6],"method":[7,73,222],"has":[8,20],"the":[9,54,87,92,107,110,120,126,130,143,154,163,170,173,179,189,193,199,203,214,229,245],"advantage":[10],"of":[11,53,94,138,176,185,202,211,233,248],"acquiring":[12],"observations":[13,89],"continuously":[14],"in":[15,24,40,42,136,153,223,237],"all":[16],"weather":[17],"conditions,":[18],"which":[19,241],"great":[21],"application":[22],"potential":[23],"vegetation":[25,55,82,249],"remote":[26],"sensing.":[27],"However,":[28],"L-band":[29],"electromagnetic":[30],"wave":[31],"signals":[32],"are":[33,59],"susceptible":[34],"to":[35,61,74,105,243],"various":[36],"environmental":[37],"factors,":[38],"resulting":[39],"deviations":[41],"GPS-IR":[43],"observation":[44,145,235],"data":[45,77,146,236],"at":[46],"certain":[47],"times.":[48],"accuracy":[50,230],"and":[51,129,178,213,231],"reliability":[52],"index":[56,83,115],"retrieving":[57,79,134,169,197],"results":[58,160,190],"challenging":[60],"achieve":[62],"by":[63,148,192,208,218],"using":[64],"single-frequency":[65,132,195],"GPS":[66,150],"data.":[67],"This":[68],"letter":[69,225],"proposed":[70,127,164,221],"a":[71,98],"novel":[72],"combine":[75],"dual-frequency":[76],"for":[78,168],"normalized":[80,112],"difference":[81],"(NDVI).":[84],"We":[85],"integrated":[86],"multipath":[88],"based":[90,141],"on":[91,142],"theory":[93],"information":[95],"entropy.":[96],"Subsequently,":[97],"unary":[99],"linear":[100],"regression":[101],"model":[102,128,135,165],"was":[103,123,206,216],"established":[104],"retrieve":[106],"NDVI":[108,133,196,205,234],"from":[109],"calculated":[111],"microwave":[113],"reflection":[114],"(NMRI).":[116],"For":[117],"validation":[118],"purposes,":[119],"comparative":[121],"analysis":[122],"conducted":[124],"between":[125],"previous":[131,194],"terms":[137],"retrieval":[139],"accuracy,":[140],"continuous":[144],"acquired":[147,191],"four":[149],"reference":[151],"stations":[152],"past":[155],"five":[156],"years.":[157],"experimental":[159],"indicated":[161],"that":[162],"is":[166],"available":[167],"NDVI,":[171],"with":[172,188],"correlation":[174,200],"coefficient":[175,201],"0.749\u20130.815":[177],"root":[180],"mean":[181],"square":[182],"error":[183],"(RMSE)":[184],"0.056\u20130.081.":[186],"Compared":[187],"model,":[198],"retrieved":[204],"increased":[207],"an":[209],"average":[210],"18.5%,":[212],"RMSE":[215],"reduced":[217],"30.3%.":[219],"this":[224],"helps":[226],"further":[227],"improve":[228],"continuity":[232],"some":[238],"local":[239],"areas,":[240],"contributes":[242],"grasping":[244],"growth":[246],"status":[247],"comprehensively.":[250]},"counts_by_year":[{"year":2025,"cited_by_count":2},{"year":2024,"cited_by_count":2},{"year":2022,"cited_by_count":2}],"updated_date":"2026-03-27T05:58:40.876381","created_date":"2025-10-10T00:00:00"}
