{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,5]],"date-time":"2026-03-05T06:39:20Z","timestamp":1772692760898,"version":"3.50.1"},"reference-count":71,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2022,3,15]],"date-time":"2022-03-15T00:00:00Z","timestamp":1647302400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["41505036"],"award-info":[{"award-number":["41505036"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Talent programme of Gansu Meteorological Bureau","award":["2122rczx-srjh-01"],"award-info":[{"award-number":["2122rczx-srjh-01"]}]},{"name":"Innovation Team Project of Gansu Meteorological Bureau","award":["GXQXCXTD-2020-01"],"award-info":[{"award-number":["GXQXCXTD-2020-01"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Accurately obtaining the spatial distribution of soil moisture and its variability are the basis for the land-atmosphere interaction study. We investigated the fidelity of four satellite-based soil moisture products (AMSR2, CCI, SMAP, and SMOS) using in situ observation during the period 2019\u20132020. The spatial distribution and variability of different soil moisture products in northern China were analyzed for different seasons and climate zones. The satellite products showed the best performance of summer soil moisture with the bias and uncertainty of the three products (CCI, SMAP, and SMOS) being less than 0.041 and 0.097, whereas soil moisture showed a large bias in winter. For all seasons, AMSR2 and CCI demonstrated a positive bias whereas SMAP and SMOS showed a negative bias. CCI product had little bias in spring, summer, and fall in northern China, while SMAP and SMOS had the smallest bias in winter. For different climate zones, CCI product performed better in describing the temporal variability of soil moisture in arid climate zones with the correlation coefficients &gt; 0.50 for most areas, while AMSR2 product provided a similar spatial distribution. In the eastern monsoon region, the soil moisture from SMAP and SMOS was found to have a large bias, whereas the bias in CCI product was small. Four products failed to reproduce the observed soil moisture characteristics in the transitional zones affected by the summer monsoon, with a positive bias found in AMSR2 and CCI and the largest biases in SMAP and SMOS products. We also suggest several reasons for the bias and error in the satellite soil moisture products. These results have important implications for soil moisture studies over midlatitude regions.<\/jats:p>","DOI":"10.3390\/rs14061419","type":"journal-article","created":{"date-parts":[[2022,3,16]],"date-time":"2022-03-16T03:36:23Z","timestamp":1647401783000},"page":"1419","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Validation of Four Satellite-Derived Soil Moisture Products Using Ground-Based In Situ Observations over Northern China"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8779-2079","authenticated-orcid":false,"given":"Weicheng","family":"Liu","sequence":"first","affiliation":[{"name":"Lanzhou Central Meteorological Observatory, Lanzhou 730020, China"},{"name":"College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China"}]},{"given":"Jixin","family":"Wang","sequence":"additional","affiliation":[{"name":"Lanzhou Central Meteorological Observatory, Lanzhou 730020, China"}]},{"given":"Falei","family":"Xu","sequence":"additional","affiliation":[{"name":"College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China"}]},{"given":"Chenrui","family":"Li","sequence":"additional","affiliation":[{"name":"Lanzhou Central Meteorological Observatory, Lanzhou 730020, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1183-5260","authenticated-orcid":false,"given":"Tao","family":"Xian","sequence":"additional","affiliation":[{"name":"Department of Mechanics and Aerospace Engineering, Southern University of Science and Technology, Shenzhen 518055, China"}]}],"member":"1968","published-online":{"date-parts":[[2022,3,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1016\/j.earscirev.2010.02.004","article-title":"Investigating soil moisture--climate interactions in a changing climate: A review","volume":"99","author":"Seneviratne","year":"2010","journal-title":"Earth Sci. Rev."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1839","DOI":"10.1029\/1999WR900047","article-title":"Ground-based investigation of soil moisture variability within remote sensing footprints During the Southern Great Plains 1997 (SGP97) Hydrology Experiment","volume":"35","author":"Famiglietti","year":"2010","journal-title":"Water Resour. Res."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"RG2002","DOI":"10.1029\/2011RG000372","article-title":"Upscaling sparse ground-based soil moisture observations for the validation of coarse-resolution satellite soil moisture products","volume":"50","author":"Crow","year":"2012","journal-title":"Rev. Geophy."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1016\/j.rse.2015.03.010","article-title":"Evaluation of post-retrieval de-noising of active and passive microwave satellite soil moisture","volume":"163","author":"Su","year":"2015","journal-title":"Remote Sens. Environ."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1016\/S0034-4257(01)00275-9","article-title":"Evaluating land surface moisture conditions from the remotely sensed temperature\/vegetation index measurements: An exploration with the simplified simple biosphere model","volume":"79","author":"Goward","year":"2002","journal-title":"Remote Sens. Environ."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1327","DOI":"10.1016\/j.agrformet.2009.03.004","article-title":"Estimating volumetric surface moisture content for cropped soils using a soil wetness index based on surface temperature and NDVI","volume":"149","author":"Mallick","year":"2009","journal-title":"Agric. For. Meteorol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1016\/0022-1694(95)02968-0","article-title":"Radar mapping of surface soil moisture","volume":"184","author":"Ulaby","year":"1996","journal-title":"J. Hydrol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1007\/s41976-019-00025-7","article-title":"A Review of Satellite-Derived Soil Moisture and Its Usage for Flood Estimation","volume":"2","author":"Kim","year":"2019","journal-title":"Remote Sens. Earth Syst. Sci."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"D11103","DOI":"10.1029\/2004JD005087","article-title":"Sensitivity of satellite microwave and infrared observations to soil moisture at a global scale: 2. Global statistical relationships","volume":"110","author":"Prigent","year":"2005","journal-title":"J. Geophys. Res.-Atmos."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"L17401","DOI":"10.1029\/2006GL027231","article-title":"Evaluation of ERS scatterometer soil moisture products over a half-degree region in southwestern France","volume":"33","author":"Pellarin","year":"2006","journal-title":"Geophys. Res. Lett."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1016\/j.advwatres.2017.09.006","article-title":"Four decades of microwave satellite soil moisture observations: Part 1. A review of retrieval algorithms","volume":"109","author":"Karthikeyan","year":"2017","journal-title":"Adv. Water Resour."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"507","DOI":"10.1016\/S0034-4257(03)00052-X","article-title":"Soil moisture estimates from TRMM Microwave Imager observations over the Southern United States","volume":"85","author":"Bindlish","year":"2003","journal-title":"Remote Sens. Environ."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"215","DOI":"10.1016\/j.rse.2011.11.017","article-title":"Evaluation of remotely sensed and modelled soil moisture products using global ground-based in situ observations","volume":"118","author":"Albergel","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"423","DOI":"10.5194\/hess-16-423-2012","article-title":"Comparing soil moisture retrievals from SMOS and ASCAT over France","volume":"16","author":"Parrens","year":"2012","journal-title":"Hydrol. Earth Syst. Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3142","DOI":"10.1016\/j.rse.2008.03.007","article-title":"Evaluation of AMSR-E soil moisture results using the in-situ data over the Little River Experimental Watershed, Georgia","volume":"112","author":"Sahoo","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"703","DOI":"10.1016\/j.rse.2008.11.011","article-title":"An evaluation of AMSR-E derived soil moisture over Australia","volume":"113","author":"Draper","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_17","first-page":"28","article-title":"Validation of the ESA CCI Soil Moisture Product in China","volume":"48","author":"An","year":"2016","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1016\/j.advwatres.2017.09.010","article-title":"Four Decades of Microwave Satellite Soil Moisture Observations: Part 2. Product Validation and Inter-Satellite Comparisons","volume":"109","author":"Karthikeyan","year":"2017","journal-title":"Adv. Water Resour."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"112891","DOI":"10.1016\/j.rse.2022.112891","article-title":"Assessment of 24 Soil Moisture Datasets Using a New in Situ Network in the Shandian River Basin of China","volume":"271","author":"Zheng","year":"2022","journal-title":"Remote Sens. Environ."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"779","DOI":"10.1109\/LGRS.2011.2114872","article-title":"Error Estimates for Near-Real-Time Satellite Soil Moisture as Derived From the Land Parameter Retrieval Model","volume":"8","author":"Parinussa","year":"2011","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2013","DOI":"10.1007\/s00382-019-05098-0","article-title":"A sensitivity study on the response of convection initiation to in situ soil moisture in the central United States","volume":"54","author":"Yuan","year":"2020","journal-title":"Clim. Dyn."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"111812","DOI":"10.1016\/j.rse.2020.111812","article-title":"Improvement of the soil-atmosphere interactions and subsequent heavy precipitation modelling by enhanced initialization using remotely sensed 1 km soil moisture information","volume":"246","author":"Helgert","year":"2020","journal-title":"Remote Sens. Environ."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"223","DOI":"10.1080\/16742834.2011.11446933","article-title":"Evaluation of AMSR -E-Derived Soil Moisture over Northern China","volume":"4","author":"Zhang","year":"2011","journal-title":"Atmos. Ocean. Sci. Lett."},{"key":"ref_24","first-page":"67","article-title":"Top-Layer Soil Moisture Retrieval over the Qinghai-Xizang Plateau in Summer Based on AMSR-E Data","volume":"36","author":"Li","year":"2017","journal-title":"Plateau Meteorol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"703","DOI":"10.1007\/s11430-018-9308-9","article-title":"Evaluation of the SMOS and SMAP soil moisture products under different vegetation types against two sparse in situ networks over arid mountainous watersheds, Northwest China","volume":"62","author":"Zhang","year":"2019","journal-title":"Sci. China Earth Sci."},{"key":"ref_26","first-page":"85","article-title":"Comparative evaluation of SMAP & CCI & CLDAS soil moisture products in typical region of Qinghai-Tibet Plateau","volume":"15","author":"Jing","year":"2020","journal-title":"J. Subtrop. Resour. Environ."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"117","DOI":"10.2151\/jmsj.2015-008","article-title":"First Assessment of the Advanced Microwave Scanning Radiometer 2 (AMSR2)Soil Moisture Contents in Northeast Asia","volume":"93","author":"Cho","year":"2015","journal-title":"J. Meteor. Soc. Jpn."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1125","DOI":"10.1175\/BAMS-D-11-00049.1","article-title":"NASA\u2019s Soil Moisture Active Passive (SMAP) Mission and Opportunities for Applications Users","volume":"94","author":"Brown","year":"2013","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"931","DOI":"10.1016\/j.rse.2017.08.025","article-title":"Development and assessment of the SMAP enhanced passive soil moisture product","volume":"204","author":"Chan","year":"2018","journal-title":"Remote Sens. Environ."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1016\/j.rse.2014.10.005","article-title":"SMOS soil moisture product evaluation over West-Africa from local to regional scale","volume":"156","author":"Louvet","year":"2015","journal-title":"Remote Sens. Environ."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"469","DOI":"10.1016\/j.rse.2018.02.010","article-title":"CCI soil moisture assessment with SMOS soil moisture and in situ data under different environmental conditions and spatial scales in Spain","volume":"225","author":"Pablos","year":"2019","journal-title":"Remote Sens. Environ."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1016\/j.rse.2017.07.001","article-title":"ESA CCI Soil Moisture for improved Earth system understanding: State-of-the art and future directions","volume":"203","author":"Dorigo","year":"2017","journal-title":"Remote Sens. Environ."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"717","DOI":"10.5194\/essd-11-717-2019","article-title":"Evolution of the ESA CCI Soil Moisture climate data records and their underlying merging methodology","volume":"11","author":"Gruber","year":"2019","journal-title":"Earth Syst. Sci. Data"},{"key":"ref_34","first-page":"122","article-title":"Spatiotemporal Variations of Soil Moisture in the Tarim River Basin, China","volume":"48","author":"Su","year":"2016","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Wang, Y., Yang, J., Chen, Y., Wang, A., and De Maeyer, P. (2018). The Spatiotemporal Response of Soil Moisture to Precipitation and Temperature Changes in an Arid Region, China. Remote Sens., 10.","DOI":"10.3390\/rs10030468"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1149","DOI":"10.1214\/aos\/1176342563","article-title":"Minimax Estimation of a Cumulative Distribution Function","volume":"1","author":"Phadia","year":"1973","journal-title":"Ann. Stat."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"679","DOI":"10.1016\/j.ijforecast.2006.03.001","article-title":"Another look at measures of forecast accuracy","volume":"22","author":"Hyndman","year":"2006","journal-title":"Int. J. Forecast."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"7183","DOI":"10.1029\/2000JD900719","article-title":"Summarizing multiple aspects of model performance in a single diagram","volume":"106","author":"Taylor","year":"2001","journal-title":"J. Geophys. Res.-Atmos."},{"key":"ref_39","first-page":"289","article-title":"Quality Evaluation of Multi-Microwave Remote Sensing Soil Moisture Products over China","volume":"35","author":"Zhuang","year":"2015","journal-title":"J. Meteorol. Sci."},{"key":"ref_40","first-page":"1533","article-title":"Variation Characteristics of Precipitation and Its Affecting Factors in Northwest China over the Past 55 Years","volume":"36","author":"Liu","year":"2017","journal-title":"Plateau Meteorol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"15729","DOI":"10.3390\/rs71115729","article-title":"Evaluation of satellite and reanalysis soil moisture products over Southwest China using ground-based measurements","volume":"7","author":"Peng","year":"2015","journal-title":"Remote Sens."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"141","DOI":"10.5194\/hess-14-141-2010","article-title":"Soil moisture active and passive microwave products: Intercomparison and evaluation over a Sahelian site","volume":"14","author":"Gruhier","year":"2010","journal-title":"Hydrol. Earth Syst. Sci."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1423","DOI":"10.1175\/2010JHM1285.1","article-title":"Estimating spatial sampling errors in coarse-scale soil moisture estimates derived from point-scale observations","volume":"11","author":"Miralles","year":"2010","journal-title":"J. Hydrometeorol."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"D15107","DOI":"10.1029\/2011JD015633","article-title":"An intercomparison of available soil moisture estimates from thermal infrared and passive microwave remote sensing and land surface modeling","volume":"116","author":"Hain","year":"2011","journal-title":"J. Geophys. Res.-Atmos."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"436","DOI":"10.1002\/met.1473","article-title":"An introduction to factor analysis for radio frequency interference detection on satellite observations","volume":"22","author":"Isla","year":"2015","journal-title":"Meteorol. Appl."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"3161","DOI":"10.1007\/s11269-017-1722-6","article-title":"Satellite Soil Moisture: Review of Theory and Applications in Water Resources","volume":"31","author":"Srivastava","year":"2017","journal-title":"Water Resour. Manag."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"1354","DOI":"10.1109\/TGRS.2012.2187666","article-title":"ESA\u2019s soil moisture and ocean salinity mission: Mission performance and operations","volume":"50","author":"Mecklenburg","year":"2012","journal-title":"IEEE Trans. Geosci. Remote"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"515","DOI":"10.1109\/LGRS.2012.2211993","article-title":"A study of SMOS RFI over North America","volume":"10","author":"Aksoy","year":"2013","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"4973","DOI":"10.1109\/TGRS.2013.2253472","article-title":"RFI characterization and mitigation for the SMAP radar","volume":"51","author":"Spencer","year":"2013","journal-title":"IEEE Trans. Geosci. Remote"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"761","DOI":"10.1109\/TGRS.2013.2281266","article-title":"Radio-frequency interference mitigation for the soil moisture active passive microwave radiometer","volume":"52","author":"Piepmeier","year":"2014","journal-title":"IEEE Trans. Geosci. Remote"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"2082","DOI":"10.1109\/TGRS.2015.2495365","article-title":"A Field Verification of an Algorithm for Retrieving Vegetation Water Content From Passive Microwave Observations","volume":"54","author":"Sawada","year":"2015","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"4473","DOI":"10.5194\/hess-22-4473-2018","article-title":"Estimating time-dependent vegetation biases in the SMAP soil moisture product. Hydrol","volume":"22","author":"Zwieback","year":"2018","journal-title":"Earth Syst. Sci."},{"key":"ref_53","first-page":"d05102","article-title":"Evaluation of multireanalysis products with in situ observations over the Tibetan Plateau","volume":"117","author":"Wang","year":"2012","journal-title":"J. Geophys. Res.-Atmos."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"240","DOI":"10.1016\/j.rse.2013.02.017","article-title":"Spatial distribution and possible sources of SMOS errors at the global scale","volume":"13","author":"Leroux","year":"2013","journal-title":"Remote Sens. Environ."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1016\/j.rse.2017.04.019","article-title":"A comparison of SMOS and AMSR2 soil moisture using representative sites of the OzNet monitoring network","volume":"195","author":"Yee","year":"2017","journal-title":"Remote Sens. Environ."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1038\/ngeo2868","article-title":"The global distribution and dynamics of surface soil moisture","volume":"10","author":"McColl","year":"2017","journal-title":"Nat. Geosci."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"1831","DOI":"10.1007\/s00704-019-02907-8","article-title":"Inhomogeneity of precipitation and its influencing factors in Northwest China from 1961 to 2015. Theor","volume":"138","author":"Liu","year":"2019","journal-title":"Appl. Clim."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"111806","DOI":"10.1016\/j.rse.2020.111806","article-title":"Validation Practices for Satellite Soil Moisture Retrievals: What Are (the) Errors?","volume":"244","author":"Gruber","year":"2020","journal-title":"Remote Sens. Environ."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"5749","DOI":"10.5194\/hess-25-5749-2021","article-title":"The International Soil Moisture Network: Serving Earth System Science for over a Decade","volume":"25","author":"Dorigo","year":"2021","journal-title":"Hydrol. Earth Syst. Sci."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"687","DOI":"10.1002\/2013WR013807","article-title":"Calibrating a large-extent high-resolution coupled groundwater-land surface model using soil moisture and discharge data","volume":"50","author":"Sutanudjaja","year":"2014","journal-title":"Water Resour. Res."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"4191","DOI":"10.5194\/hess-20-4191-2016","article-title":"Combining satellite observations to develop a global soil moisture product for near-real-time applications","volume":"20","author":"Enenkel","year":"2016","journal-title":"Hydrol. Earth Syst. Sci."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"280","DOI":"10.1016\/j.rse.2012.03.014","article-title":"Trend-preserving blending of passive and active microwave soil moisture retrievals","volume":"123","author":"Liu","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_63","doi-asserted-by":"crossref","unstructured":"Cheng, M., Zhong, L., Ma, Y., Zou, M., Ge, N., Wang, X., and Hu, Y. (2019). A study on the assessment of multi-source satellite soil moisture products and reanalysis data for the Tibetan Plateau. Remote Sens., 11.","DOI":"10.3390\/rs11101196"},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"111224","DOI":"10.1016\/j.rse.2019.111224","article-title":"Extending the SMAP 9-km soil moisture product using a spatio-temporal fusion model","volume":"231","author":"Jiang","year":"2019","journal-title":"Remote Sens. Environ."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"341","DOI":"10.1002\/2016RG000543","article-title":"A review of spatial downscaling of satellite remotely sensed soil moisture","volume":"55","author":"Peng","year":"2017","journal-title":"Rev. Geophys."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"124711","DOI":"10.1016\/j.jhydrol.2020.124711","article-title":"Stochastic analysis and probabilistic downscaling of soil moisture in small catchments","volume":"585","author":"Deshon","year":"2020","journal-title":"J. Hydrol."},{"key":"ref_67","doi-asserted-by":"crossref","unstructured":"Xu, C., Qu, J.J., Hao, X., Cosh, M.H., Prueger, J.H., Zhu, Z., and Gutenberg, L. (2018). Downscaling of Surface Soil Moisture Retrieval by Combining MODIS\/Landsat and In Situ Measurements. Remote Sens., 10.","DOI":"10.3390\/rs10020210"},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"3507","DOI":"10.1109\/TGRS.2014.2378913","article-title":"Copula-Based Downscaling of Coarse-Scale Soil Moisture Observations With Implicit Bias Correction","volume":"53","author":"Verhoest","year":"2015","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_69","doi-asserted-by":"crossref","unstructured":"Montzka, C., R\u00f6tzer, K., Bogena, H.R., Sanchez, N., and Vereecken, H. (2018). A New Soil Moisture Downscaling Approach for SMAP, SMOS, and ASCAT by Predicting Sub-Grid Variability. Remote Sens., 10.","DOI":"10.3390\/rs10030427"},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"640","DOI":"10.1109\/TGRS.2015.2450694","article-title":"Uncertainty estimates in the SMAP combined active-passive downscaled brightness temperature","volume":"54","author":"Das","year":"2016","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"785","DOI":"10.1016\/j.advwatres.2004.05.006","article-title":"Requirements of a global near-surface soil moisture satellite mission: Accuracy, repeat time, and spatial resolution","volume":"27","author":"Walker","year":"2004","journal-title":"Adv. Water Resour."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/6\/1419\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T22:36:56Z","timestamp":1760135816000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/14\/6\/1419"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,3,15]]},"references-count":71,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2022,3]]}},"alternative-id":["rs14061419"],"URL":"https:\/\/doi.org\/10.3390\/rs14061419","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,3,15]]}}}