{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,11]],"date-time":"2025-11-11T13:29:29Z","timestamp":1762867769039,"version":"build-2065373602"},"reference-count":33,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2019,3,16]],"date-time":"2019-03-16T00:00:00Z","timestamp":1552694400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000900","name":"Joint Research Centre","doi-asserted-by":"publisher","award":["932059"],"award-info":[{"award-number":["932059"]}],"id":[{"id":"10.13039\/501100000900","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Surface albedo is of crucial interest in land\u2013climate interaction studies, since it is a key parameter that affects the Earth\u2019s radiation budget. The temporal and spatial variation of surface albedo can be retrieved from conventional satellite observations after a series of processes, including atmospheric correction to surface spectral bi-directional reflectance factor (BRF), bi-directional reflectance distribution function (BRDF) modelling using these BRFs, and, where required, narrow-to-broadband albedo conversions. This processing chain introduces errors that can be accumulated and then affect the accuracy of the retrieved albedo products. In this study, the albedo products derived from the multi-angle imaging spectroradiometer (MISR), moderate resolution imaging spectroradiometer (MODIS) and the Copernicus Global Land Service (CGLS), based on the VEGETATION and now the PROBA-V sensors, are compared with albedometer and upscaled in situ measurements from 19 tower sites from the FLUXNET network, surface radiation budget network (SURFRAD) and Baseline Surface Radiation Network (BSRN) networks. The MISR sensor onboard the Terra satellite has 9 cameras at different view angles, which allows a near-simultaneous retrieval of surface albedo. Using a 16-day retrieval algorithm, the MODIS generates the daily albedo products (MCD43A) at a 500-m resolution. The CGLS albedo products are derived from the VEGETATION and PROBA-V, and updated every 10 days using a weighted 30-day window. We describe a newly developed method to derive the two types of albedo, which are directional hemispherical reflectance (DHR) and bi-hemispherical reflectance (BHR), directly from three tower-measured variables of shortwave radiation: downwelling, upwelling and diffuse shortwave radiation. In the validation process, the MISR, MODIS and CGLS-derived albedos (DHR and BHR) are first compared with tower measured albedos, using pixel-to-point analysis, between 2012 to 2016. The tower measured point albedos are then upscaled to coarse-resolution albedos, based on atmospherically corrected BRFs from high-resolution Earth observation (HR-EO) data, alongside MODIS BRDF climatology from a larger area. Then a pixel-to-pixel comparison is performed between DHR and BHR retrieved from coarse-resolution satellite observations and DHR and BHR upscaled from accurate tower measurements. The experimental results are presented on exploring the parameter space associated with land cover type, heterogeneous vs. homogeneous and instantaneous vs. time composite retrievals of surface albedo.<\/jats:p>","DOI":"10.3390\/rs11060644","type":"journal-article","created":{"date-parts":[[2019,3,18]],"date-time":"2019-03-18T12:18:53Z","timestamp":1552911533000},"page":"644","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":25,"title":["Intercomparison of Surface Albedo Retrievals from MISR, MODIS, CGLS Using Tower and Upscaled Tower Measurements"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3744-695X","authenticated-orcid":false,"given":"Rui","family":"Song","sequence":"first","affiliation":[{"name":"Imaging Group, Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5077-3736","authenticated-orcid":false,"given":"Jan-Peter","family":"Muller","sequence":"additional","affiliation":[{"name":"Imaging Group, Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Said","family":"Kharbouche","sequence":"additional","affiliation":[{"name":"Imaging Group, Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"William","family":"Woodgate","sequence":"additional","affiliation":[{"name":"Building 801, CSIRO, Black Mountain, Canberra 2601, Australia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,3,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"305","DOI":"10.1016\/S0065-2687(08)60176-4","article-title":"Land surface processes and climate-surface albedos and energy balance","volume":"25","author":"Dickinson","year":"1983","journal-title":"Adv. Geophys."},{"key":"ref_2","unstructured":"Gurney, R.J., Foster, J.L., and Parkinson, C.L. (1993). Radiation budget at the top of the atmosphere. Atlas of Satellite Observations Related to Global Change, Cambridge University Press."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"302","DOI":"10.1109\/36.134080","article-title":"Remote sensing of solar radiation absorbed and reflected by vegetated land surfaces","volume":"30","author":"Myneni","year":"1992","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"303","DOI":"10.1175\/1520-0477-29.6.303","article-title":"The Albedo of the Ground and Atmosphere","volume":"29","author":"Fritz","year":"1948","journal-title":"Bull. Am. Meteorol. Soc."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1491","DOI":"10.5194\/essd-10-1491-2018","article-title":"Baseline Surface Radiation Network (BSRN): Structure and data description (1992\u20132017)","volume":"10","author":"Driemel","year":"2018","journal-title":"Earth Syst. Sci. Data"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1460","DOI":"10.1175\/JTECH1806.1","article-title":"An update on SURFRAD--the GCOS Surface Radiation Budget Network for the Continental United States","volume":"22","author":"Augustine","year":"2005","journal-title":"J. Atmos. Ocean. Technol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"741","DOI":"10.1175\/1520-0450(1985)024<0741:ANTFIS>2.0.CO;2","article-title":"A New Technique for Inferring Surface Albedo from Satellite Observations","volume":"24","author":"Pinty","year":"1985","journal-title":"J. Appl. Meteorol. Climatol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"973","DOI":"10.1175\/1520-0450(1988)027<0973:ASMFEM>2.0.CO;2","article-title":"A Simple Method for Estimating Monthly Mean Albedo of Land Surfaces from AVHRR Data","volume":"27","author":"Gutman","year":"1988","journal-title":"J. Appl. Meteorol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"6215","DOI":"10.1029\/1998JD200090","article-title":"Mapping global land surface albedo from NOAA AVHRR","volume":"104","author":"Csiszar","year":"1999","journal-title":"J. Geophys. Res. Solid Earth"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1016\/S0034-4257(02)00092-5","article-title":"Validating MODIS land surface reflectance and albedo products: Methods and preliminary results","volume":"83","author":"Liang","year":"2002","journal-title":"Remote Sens. Environ."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"323","DOI":"10.1016\/j.rse.2012.02.019","article-title":"Intercomparison of MODIS albedo retrievals and in situ measurements across the global FLUXNET network","volume":"121","author":"Cescatti","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_12","unstructured":"Strahler, A., Muller, J.-P., Lucht, W., Schaaf, C., Tsang, T., Gao, F., Xiaowen, L., Lewis, P., and Barnsley, M.J. (2019, January 12). MODIS BRDF Albedo Product Algorithm Theoretical Basis Document Version 5.0, Available online: https:\/\/modis.gsfc.nasa.gov\/data\/atbd\/atbd_mod09.pdf."},{"key":"ref_13","unstructured":"Lacaze, R., Smets, B., Trigo, I., Calvet, J.C., Jann, A., Camacho, F., Baret, F., Kidd, R., Defourny, P., and Tansey, K. (2013, January 7\u201312). The Copernicus Global Land Service: Present and future. Proceedings of the EGU General Assembly, Vienna, Austria."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/S0034-4257(02)00091-3","article-title":"First operational BRDF, albedo nadir reflectance products from MODIS","volume":"83","author":"Schaaf","year":"2002","journal-title":"Remote Sens. Environ."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1266","DOI":"10.1109\/36.701077","article-title":"Determination of land and ocean reflective, radiative, and biophysical properties using multiangle imaging","volume":"36","author":"Martonchik","year":"1998","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_16","unstructured":"NOAA (2018, September 01). SURFRAD Overview: Surface Radiation Budget Monitoring, Available online: https:\/\/www.esrl.noaa.gov\/gmd\/grad\/surfrad\/overview.html."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1072","DOI":"10.1109\/36.700992","article-title":"Multi-angle Imaging SpectroRadiometer (MISR) instrument description and experiment overview","volume":"36","author":"Diner","year":"1998","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1016\/S0034-4257(00)00205-4","article-title":"Narrowband to broadband conversions of land surface albedo: I Algorithms","volume":"76","author":"Liang","year":"2000","journal-title":"Remote Sens. Environ."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1016\/j.rse.2006.03.002","article-title":"Reflectance quantities in optical remote sensing\u2014definitions and case studies","volume":"103","author":"Schaepman","year":"2006","journal-title":"Remote Sens. Environ."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"977","DOI":"10.1109\/36.841980","article-title":"An algorithm for the retrieval of albedo from space using semiempirical BRDF models","volume":"38","author":"Lucht","year":"2000","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1393","DOI":"10.1109\/TGRS.2013.2243457","article-title":"Use of in situ and airborne multiangle data to assess MODIS- and Landsat-based estimates of directional reflectance and albedo","volume":"51","author":"Gatebe","year":"2013","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_22","unstructured":"Muller, J.-P. (2019, January 10). GlobAlbedo Final Product Validation Report 2012. Available online: http:\/\/www.globalbedo.org\/docs\/GlobAlbedo_FVR_V1_2_web.pdf."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Mousavi Maleki, S.A., Hizam, H., and Gomes, C. (2017). Estimation of Hourly, Daily and Monthly Global Solar Radiation on Inclined Surfaces: Models Re-Visited. Energies, 10.","DOI":"10.3390\/en10010134"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1016\/j.rse.2016.06.013","article-title":"Coarse scale in situ albedo observations over heterogeneous snow-free land surfaces and validation strategy: A case of MODIS albedo products preliminary validation over northern China","volume":"184","author":"Wu","year":"2016","journal-title":"Remote Sens. Environ."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"136","DOI":"10.1109\/TGRS.2002.807751","article-title":"A direct algorithm for estimating land surface broadband albedos from MODIS imagery","volume":"41","author":"Liang","year":"2003","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"990","DOI":"10.3390\/rs70100990","article-title":"Mapping surface broadband albedo from satellite observations: A review of literatures on algorithms and products","volume":"7","author":"Qu","year":"2015","journal-title":"Remote Sens."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"2204","DOI":"10.1016\/j.rse.2011.04.019","article-title":"An algorithm for the retrieval of 30-m snow-free albedo from Landsat surface reflectance and MODIS BRDF","volume":"115","author":"Shuai","year":"2011","journal-title":"Remote Sens. Environ."},{"key":"ref_28","unstructured":"Muller, J.P., Lopez-Saldana, G., Kharbouche, S., Danne, O., Lattanzio, A., Schulz, J., and Lewis, P. (2019). Optimal estimation for the retrieval of traceable and validated albedo: Lessons learnt from the ESA-GlobAlbedo and EU-QA4ECV projects, in preparation."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Winter, M.E. (1999, January 27). N-FINDR: An algorithm for fast autonomous spectral end-member determination in hyperspectral data. Proceedings of the SPIE 3753, Imaging Spectrometry V, Denver, CO, USA.","DOI":"10.1117\/12.366289"},{"key":"ref_30","unstructured":"Heinz, D., Chang, C.-I., and Althouse, M.L.G. (July, January 28). Fully constrained least-squares based linear unmixing hyperspectral image classification. Proceedings of the IEEE 1999 International Geoscience and Remote Sensing Symposium, Hamburg, Germany."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"126","DOI":"10.1016\/j.jqsrt.2016.04.005","article-title":"A model-based framework for the quality assessment of surface albedo in situ measurement protocols","volume":"180","author":"Adams","year":"2016","journal-title":"J. Quant. Spectrosc. Radiat. Transf."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"397","DOI":"10.1016\/0038-092X(95)00017-L","article-title":"Cosine response characteristics of some radiometric and photometric sensors","volume":"54","author":"Michalsky","year":"1995","journal-title":"Sol. Energy"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"738","DOI":"10.1016\/j.rse.2009.11.014","article-title":"Assessing the coupling between surface albedo derived from MODIS and the fraction of diffuse skylight over spatially-characterized landscapes","volume":"114","author":"Schaaf","year":"2010","journal-title":"Remote Sens. Environ."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/11\/6\/644\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T12:38:21Z","timestamp":1760186301000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/11\/6\/644"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,3,16]]},"references-count":33,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2019,3]]}},"alternative-id":["rs11060644"],"URL":"https:\/\/doi.org\/10.3390\/rs11060644","relation":{},"ISSN":["2072-4292"],"issn-type":[{"type":"electronic","value":"2072-4292"}],"subject":[],"published":{"date-parts":[[2019,3,16]]}}}