{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,12]],"date-time":"2026-06-12T21:03:22Z","timestamp":1781298202162,"version":"3.54.1"},"reference-count":66,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2020,6,19]],"date-time":"2020-06-19T00:00:00Z","timestamp":1592524800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001413","name":"Indian Space Research Organisation","doi-asserted-by":"publisher","award":["P32\/21"],"award-info":[{"award-number":["P32\/21"]}],"id":[{"id":"10.13039\/501100001413","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Space-borne soil moisture (SM) satellite products such as those available from Soil Moisture Active Passive (SMAP) offer unique opportunities for global and frequent monitoring of SM and also to understand its spatiotemporal variability. The present study investigates the performance of the SMAP L4 SM product at selected experimental sites across four continents, namely North America, Europe, Asia and Australia. This product provides global scale SM estimates at 9 km \u00d7 9 km spatial resolution at daily intervals. For the product evaluation, co-orbital in situ SM measurements were used, acquired at 14 test sites in North America, Europe, and Australia belonging to the International Soil Moisture Network (ISMN) and local networks in India. The satellite SM estimates of up to 0\u20135 cm soil layer were compared against collocated ground measurements using a series of statistical scores. Overall, the best performance of the SMAP product was found in North America (RMSE = 0.05 m3\/m3) followed by Australia (RMSE = 0.08 m3\/m3), Asia (RMSE = 0.09 m3\/m3) and Europe (RMSE = 0.14 m3\/m3). Our findings provide important insights into the spatiotemporal variability of the specific operational SM product in different ecosystems and environments. This study also furnishes an independent verification of this global product, which is of international interest given its suitability for a wide range of practical and research applications.<\/jats:p>","DOI":"10.3390\/rs12121977","type":"journal-article","created":{"date-parts":[[2020,6,19]],"date-time":"2020-06-19T10:43:58Z","timestamp":1592563438000},"page":"1977","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":23,"title":["Appraisal of SMAP Operational Soil Moisture Product from a Global Perspective"],"prefix":"10.3390","volume":"12","author":[{"given":"Swati","family":"Suman","sequence":"first","affiliation":[{"name":"Remote Sensing Laboratory, Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi 221005, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Prashant K.","family":"Srivastava","sequence":"additional","affiliation":[{"name":"Remote Sensing Laboratory, Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi 221005, India"},{"name":"DST-Mahamana Centre for Excellence in Climate Change Research, Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi 221005, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"George P.","family":"Petropoulos","sequence":"additional","affiliation":[{"name":"Department of Geography, Harokopio University of Athens, El. Venizelou 70, Kallithea, 17671 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4060-5368","authenticated-orcid":false,"given":"Dharmendra K.","family":"Pandey","sequence":"additional","affiliation":[{"name":"Space Applications Centre, Indian Space Research Organization, Ahmedabad 380015, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Peggy E.","family":"O\u2019Neill","sequence":"additional","affiliation":[{"name":"Hydrological Sciences Laboratory, NASA Goddard Space Flight Centre, Greenbelt, MD 20771, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,6,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"403","DOI":"10.1016\/j.rse.2016.02.048","article-title":"Towards improved spatio-temporal resolution soil moisture retrievals from the synergy of SMOS and MSG SEVIRI spaceborne observations","volume":"180","author":"Piles","year":"2016","journal-title":"Remote Sens. 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