{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T02:15:52Z","timestamp":1760148952100,"version":"build-2065373602"},"reference-count":43,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2023,6,13]],"date-time":"2023-06-13T00:00:00Z","timestamp":1686614400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Key Research and Development Program of China","award":["2018YFC1506500","2021YFC3000300","2018YFB0504905","FY-APP-2021.0505","CMA2023QN08"],"award-info":[{"award-number":["2018YFC1506500","2021YFC3000300","2018YFB0504905","FY-APP-2021.0505","CMA2023QN08"]}]},{"name":"FengYun Application Pioneering Project","award":["2018YFC1506500","2021YFC3000300","2018YFB0504905","FY-APP-2021.0505","CMA2023QN08"],"award-info":[{"award-number":["2018YFC1506500","2021YFC3000300","2018YFB0504905","FY-APP-2021.0505","CMA2023QN08"]}]},{"name":"Youth Innovation Team of China Meteorological Administration","award":["2018YFC1506500","2021YFC3000300","2018YFB0504905","FY-APP-2021.0505","CMA2023QN08"],"award-info":[{"award-number":["2018YFC1506500","2021YFC3000300","2018YFB0504905","FY-APP-2021.0505","CMA2023QN08"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Land surface microwave emissivity is crucial to the accurate retrieval of surface and atmospheric parameters and the assimilation of microwave data into numerical models over land. The microwave radiation imager (MWRI) sensors aboard on Chinese FengYun-3 (FY-3) series satellites provide valuable measurements for the derivation of global microwave physical parameters. In this study, an approximated microwave radiation transfer equation was used to estimate land surface emissivity from MWRI by using brightness temperature observations along with corresponding land and atmospheric properties obtained from ERA-Interim reanalysis data. Surface microwave emissivity at the 10.65, 18.7, 23.8, 36.5, and 89 GHz vertical and horizontal polarizations was derived. Then, the global spatial distribution and spectrum characteristics of emissivity over different land cover types were investigated. The seasonal variations of emissivity for different surface properties were presented. Furthermore, the error source was also discussed in our emissivity derivation. The results showed that the estimated emissivity was able to capture the major large-scale features and contains a wealth of information regarding soil moisture and vegetation density. The emissivity increased with the increase in frequency. The smaller surface roughness and increased scattering effect may result in low emissivity. Desert regions showed high emissivity microwave polarization difference index (MPDI) values, which suggested the high contrast between vertical and horizontal microwave signals in this region. The emissivity of the deciduous needleleaf forest in summer was almost the greatest among different land cover types. There was a sharp decrease in the emissivity at 89 GHz in the winter, possibly due to the influence of deciduous leaves and snowfall. The land surface temperature, the radio-frequency interference, and the high-frequency channel under cloudy conditions may be the main error sources in this retrieval. This work showed the potential capabilities of providing continuous and comprehensive global surface microwave emissivity from FY-3 series satellites for a better understanding of its spatiotemporal variability and underlying processes.<\/jats:p>","DOI":"10.3390\/s23125534","type":"journal-article","created":{"date-parts":[[2023,6,13]],"date-time":"2023-06-13T02:56:34Z","timestamp":1686624994000},"page":"5534","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Surface Properties of Global Land Surface Microwave Emissivity Derived from FY-3D\/MWRI Measurements"],"prefix":"10.3390","volume":"23","author":[{"given":"Ronghan","family":"Xu","sequence":"first","affiliation":[{"name":"Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites, National Satellite Meteorological Center (National Center for Space Weather), China Meteorological Administration, Beijing 100081, China"},{"name":"Innovation Center for FengYun Meteorological Satellite (FYSIC), Beijing 100081, China"}]},{"given":"Zharong","family":"Pan","sequence":"additional","affiliation":[{"name":"General Institute of Water Resources and Hydropower Planning and Design, Ministry of Water Resources, Beijing 100120, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2049-7678","authenticated-orcid":false,"given":"Yang","family":"Han","sequence":"additional","affiliation":[{"name":"Earth System Modeling and Prediction Center, China Meteorological Administration, Beijing 100081, China"}]},{"given":"Wei","family":"Zheng","sequence":"additional","affiliation":[{"name":"Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites, National Satellite Meteorological Center (National Center for Space Weather), China Meteorological Administration, Beijing 100081, China"},{"name":"Innovation Center for FengYun Meteorological Satellite (FYSIC), Beijing 100081, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5930-3183","authenticated-orcid":false,"given":"Shengli","family":"Wu","sequence":"additional","affiliation":[{"name":"Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites, National Satellite Meteorological Center (National Center for Space Weather), China Meteorological Administration, Beijing 100081, China"},{"name":"Innovation Center for FengYun Meteorological Satellite (FYSIC), Beijing 100081, China"}]}],"member":"1968","published-online":{"date-parts":[[2023,6,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"21867","DOI":"10.1029\/97JD01360","article-title":"Microwave land surface emissivities estimated from SSM\/I observations","volume":"102","author":"Prigent","year":"1997","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"160","DOI":"10.1109\/LGRS.2004.842448","article-title":"On the Determination of Surface Emissivity From Satellite Observations","volume":"2","author":"Matzler","year":"2005","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1251","DOI":"10.1109\/TGRS.2010.2075936","article-title":"Potential Use of Surface-Sensitive Microwave Observations Over Land in Numerical Weather Prediction","volume":"49","author":"Gerard","year":"2011","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"20115","DOI":"10.1029\/2001JD900019","article-title":"A microwave land emissivity model","volume":"106","author":"Weng","year":"2001","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"378","DOI":"10.1109\/TGRS.2012.2199121","article-title":"An Evaluation of Microwave Land Surface Emissivities Over the Continental United States to Benefit GPM-Era Precipitation Algorithms","volume":"51","author":"Ferraro","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"7637","DOI":"10.1109\/TGRS.2014.2315809","article-title":"A Physically Based Soil Moisture and Microwave Emissivity Data Set for Global Precipitation Measurement (GPM) Applications","volume":"52","author":"Turk","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1270","DOI":"10.1109\/LGRS.2016.2581140","article-title":"Global Land Surface Emissivity Estimation From AMSR2 Observations","volume":"13","author":"Prakash","year":"2016","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"D16","DOI":"10.1029\/2010JD015429","article-title":"Land surface microwave emissivity derived from AMSR-E and MODIS measurements with advanced quality control","volume":"116","author":"Moncet","year":"2011","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"2333","DOI":"10.1256\/qj.05.216","article-title":"Microwave land emissivity and skin temperature for AMSU-A and -B assimilation over land","volume":"132","author":"Karbou","year":"2007","journal-title":"Q. J. R. Meteorol. Soc."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"907","DOI":"10.1175\/JAMC-D-17-0213.1","article-title":"Estimation of Consistent Global Microwave Land Surface Emissivity from AMSR-E and AMSR2 Observations","volume":"57","author":"Prakash","year":"2018","journal-title":"J. Appl. Meteorol. Clim."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2633","DOI":"10.1175\/1520-0469(2003)060<2633:SDAINW>2.0.CO;2","article-title":"Satellite Data Assimilation in Numerical Weather Prediction Models. Part I: Forward Radiative Transfer and Jacobian Modeling in Cloudy Atmospheres","volume":"60","author":"Weng","year":"2003","journal-title":"J. Atmos. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3799","DOI":"10.1175\/2007JAS2112.1","article-title":"Advances in Radiative Transfer Modeling in Support of Satellite Data Assimilation","volume":"64","author":"Weng","year":"2009","journal-title":"J. Atmos. Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2228","DOI":"10.1109\/TGRS.2007.898263","article-title":"Passive Microwave Remote Sensing of Extreme Weather Events Using NOAA-18 AMSUA and MHS","volume":"45","author":"Boukabara","year":"2007","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2717","DOI":"10.5194\/gmd-11-2717-2018","article-title":"An update on the RTTOV fast radiative transfer model (currently at version 12)","volume":"11","author":"Saunders","year":"2018","journal-title":"Geosci. Model Dev."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1007\/s00376-019-9170-2","article-title":"Advanced Radiative Transfer Modeling System (ARMS): A New-Generation Satellite Observation Operator Developed for Numerical Weather Prediction and Remote Sensing Applications","volume":"37","author":"Weng","year":"2020","journal-title":"Adv. Atmos. Sci."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1175\/JHM-D-13-08.1","article-title":"Principal Components of Multifrequency Microwave Land Surface Emissivities. Part I: Estimation under Clear and Precipitating Conditions","volume":"15","author":"Turk","year":"2014","journal-title":"J. Hydrometeorol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1573","DOI":"10.1175\/BAMS-87-11-1573","article-title":"Land Surface Microwave Emissivities over the Globe for a Decade","volume":"87","author":"Prigent","year":"2006","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3577","DOI":"10.5194\/hess-15-3577-2011","article-title":"The sensitivity of land emissivity estimates from AMSR-E at C and X bands to surface properties","volume":"15","author":"Norouzi","year":"2011","journal-title":"Hydrol. Earth Syst. Sci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2261","DOI":"10.1175\/1520-0477(1999)080<2261:AIUCFI>2.0.CO;2","article-title":"Advances in Understanding Clouds from ISCCP","volume":"80","author":"Rossow","year":"1999","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2011","DOI":"10.1016\/j.rse.2009.05.007","article-title":"Estimation of evapotranspiration in a mid-latitude forest using the Microwave Emissivity Difference Vegetation Index (EDVI)","volume":"113","author":"Li","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1038\/nature.2017.22907","article-title":"Ageing satellites put crucial sea-ice climate record at risk","volume":"551","author":"Witze","year":"2017","journal-title":"Nature"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"4986","DOI":"10.1109\/TGRS.2012.2197003","article-title":"Environmental Data Records From FengYun-3B Microwave Radiation Imager","volume":"50","author":"Yang","year":"2012","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"3126","DOI":"10.1109\/TGRS.2018.2881094","article-title":"Ascending\u2013Descending Bias Correction of Microwave Radiation Imager on Board FengYun-3C","volume":"57","author":"Xie","year":"2018","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"6686","DOI":"10.1109\/JSTARS.2021.3075969","article-title":"In-Orbit Calibration of FengYun-3C Microwave Radiation Imager: Characterization of Backlobe Intrusion for the Hot-Load Reflector","volume":"14","author":"Xie","year":"2021","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Meier, W.N., Stewart, J.S., Windnagel, A., and Fetterer, F.M. (2022). Comparison of Hemispheric and Regional Sea Ice Extent and Area Trends from NOAA and NASA Passive Microwave-Derived Climate Records. Remote Sens., 14.","DOI":"10.3390\/rs14030619"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Du, B., Ji, D., Shi, J., Wang, Y., Lei, T., Zhang, P., and Letu, H. (2020). The Retrieval of Total Precipitable Water over Global Land Based on FY-3D\/MWRI Data. Remote Sens., 12.","DOI":"10.3390\/rs12091508"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Yang, J., Jiang, L., Wu, S., Wang, G., Wang, J., and Liu, X. (2019). Development of a Snow Depth Estimation Algorithm over China for the FY-3D\/MWRI. Remote Sens., 11.","DOI":"10.3390\/rs11080977"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"4018","DOI":"10.1109\/TGRS.2020.3019408","article-title":"Global Soil Moisture Retrievals From the Chinese FY-3D Microwave Radiation Imager","volume":"59","author":"Kang","year":"2020","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"043002","DOI":"10.1088\/1748-9326\/ab09b3","article-title":"Essential gaps and uncertainties in the understanding of the roles and functions of Arctic sea ice","volume":"14","author":"Gerland","year":"2019","journal-title":"Environ. Res. Lett."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"5937","DOI":"10.1109\/TGRS.2013.2293791","article-title":"Temperature and Emissivity Separation From MSG\/SEVIRI Data","volume":"52","author":"Sobrino","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1197","DOI":"10.5194\/amt-8-1197-2015","article-title":"Assessment of the consistency among global microwave land surface emissivity products","volume":"8","author":"Norouzi","year":"2015","journal-title":"Atmos. Meas. Tech."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"3437","DOI":"10.1109\/TGRS.2011.2125794","article-title":"Error Sources in Remote Sensing of Microwave Land Surface Emissivity","volume":"49","author":"Yang","year":"2011","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"829","DOI":"10.1109\/36.58970","article-title":"Land-surface-type classification using microwave brightness temperatures from the Special Sensor Microwave\/Imager","volume":"28","author":"Neale","year":"1990","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Wu, Y., Qian, B., Bao, Y., Petropoulos, G.P., Liu, X., and Li, L. (2019). Microwave Land Emissivity Calculations over the Qinghai-Tibetan Plateau Using FY-3B\/MWRI Measurements. Remote Sens., 11.","DOI":"10.3390\/rs11192206"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1016\/j.rse.2013.02.001","article-title":"Dynamic response of microwave land surface properties to precipitation in Amazon rainforest","volume":"133","author":"Li","year":"2020","journal-title":"Remote Sens. Environ."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1055","DOI":"10.1080\/014311698215603","article-title":"The effect of soil moisture on the 37GHz microwave polarization difference index (MPDI)","volume":"19","author":"Felde","year":"2010","journal-title":"Int. J. Remote Sens."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"12250","DOI":"10.1088\/1755-1315\/17\/1\/012250","article-title":"The construction and application of the AMSR-E global microwave emissivity database","volume":"17","author":"Lijuan","year":"2014","journal-title":"IOP Conf. Ser. Earth Environ. Sci."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"393","DOI":"10.1109\/36.905247","article-title":"Airborne measurements of forest and agricultural land surface emissivity at millimeter wavelengths","volume":"39","author":"Hewison","year":"2001","journal-title":"IEEE Trans. Geosci. Remot. Sens."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"12147","DOI":"10.1029\/1999JD900153","article-title":"Microwave radiometric signatures of different surface types in deserts","volume":"104","author":"Prigent","year":"1999","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"470","DOI":"10.1016\/j.rse.2012.04.015","article-title":"Using microwave brightness temperature diurnal cycle to improve emissivity retrievals over land","volume":"123","author":"Norouzi","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Wang, X., and Zhan, Z. (2022). Microwave Emissivity of Typical Vegetated Land Types based on AMSR2. Remote Sens., 14.","DOI":"10.3390\/rs14174276"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"948","DOI":"10.1109\/TGRS.2004.837503","article-title":"Microwave land emissivity calculations using AMSU measurements","volume":"43","author":"Karbou","year":"2005","journal-title":"IEEE Trans. Geosci. Remot. Sens."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"5608","DOI":"10.1109\/JSTARS.2017.2763167","article-title":"Retrieving K-Band Instantaneous Microwave Land Surface Emissivity Based on Passive Microwave Brightness Temperature and Atmospheric Precipitable Water Vapor Data","volume":"10","author":"Zhou","year":"2017","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/12\/5534\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T19:53:49Z","timestamp":1760126029000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/23\/12\/5534"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,6,13]]},"references-count":43,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2023,6]]}},"alternative-id":["s23125534"],"URL":"https:\/\/doi.org\/10.3390\/s23125534","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2023,6,13]]}}}