{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T15:41:06Z","timestamp":1791214866889,"version":"4.1.0"},"reference-count":50,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2015,7,21]],"date-time":"2015-07-21T00:00:00Z","timestamp":1437436800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003009","name":"Science and Technology Development Fund","doi-asserted-by":"publisher","award":["5404"],"award-info":[{"award-number":["5404"]}],"id":[{"id":"10.13039\/501100003009","id-type":"DOI","asserted-by":"publisher"}]},{"name":"French AIRD"},{"name":"French Ministry of Foreign Affairs"},{"name":"UAE Government"},{"name":"Seventh Framework Programme","award":["218793"],"award-info":[{"award-number":["218793"]}]},{"name":"Seventh Framework Programme","award":["283576"],"award-info":[{"award-number":["283576"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>HelioClim-3 (HC3) is a database providing time series of the surface downwelling solar irradiance that are computed from images of the Meteosat satellites. This paper presents the validation results of the hourly global horizontal irradiance (GHI) and direct normal irradiance (DNI), i.e., beam irradiance at normal incidence, of versions four and five of HC3 at seven Egyptian sites. The validation is performed for all-sky conditions, as well as cloud-free conditions. Both versions of HC3 provide similar performances whatever the conditions. Another comparison is made with the estimates provided by the McClear database that is restricted to cloud-free conditions. All databases capture well the temporal variability of the GHI in all conditions, McClear being superior for cloud-free cases. In cloud-free conditions for the GHI, the relative root mean square error (RMSE) are fairly similar, ranging from 6% to 15%; both HC3 databases exhibit a smaller bias than McClear. McClear offers an overall better performance for the cloud-free DNI estimates. For all-sky conditions, the relative RMSE for GHI ranges from 10% to 22%, except one station, while, for the DNI, the results are not so good for the two stations with DNI measurements.<\/jats:p>","DOI":"10.3390\/rs70709269","type":"journal-article","created":{"date-parts":[[2015,7,21]],"date-time":"2015-07-21T10:17:48Z","timestamp":1437473868000},"page":"9269-9291","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":46,"title":["Validation of the Surface Downwelling Solar Irradiance Estimates of the HelioClim-3 Database in Egypt"],"prefix":"10.3390","volume":"7","author":[{"given":"Yehia","family":"Eissa","sequence":"first","affiliation":[{"name":"Masdar Institute, Research Center for Renewable Energy Mapping and Assessment, P.O. Box 54224 Abu Dhabi, UAE"},{"name":"MINES ParisTech, PSL Research University, O.I.E. \u2013 Centre Observation, Impacts, Energy,  CS 10207 \u2013 06904 Sophia Antipolis cedex, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohamed","family":"Korany","sequence":"additional","affiliation":[{"name":"Egyptian Meteorological Authority, Cairo 11599, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Youva","family":"Aoun","sequence":"additional","affiliation":[{"name":"MINES ParisTech, PSL Research University, O.I.E. \u2013 Centre Observation, Impacts, Energy,  CS 10207 \u2013 06904 Sophia Antipolis cedex, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohamed","family":"Boraiy","sequence":"additional","affiliation":[{"name":"Physics and Mathematical Engineering Department, Faculty of Engineering, Port Said University, Port Said 42526, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Magdy","family":"Abdel Wahab","sequence":"additional","affiliation":[{"name":"Astronomy and Meteorology Department, Faculty of Science, Cairo University, Giza 12613, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stephane","family":"Alfaro","sequence":"additional","affiliation":[{"name":"Laboratoire Inter-universitaire des Syst\u00e8mes Atmosph\u00e9riques, Universit\u00e9s de Paris-Est Cr\u00e9teil et Paris-Diderot, Paris 94010, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Philippe","family":"Blanc","sequence":"additional","affiliation":[{"name":"MINES ParisTech, PSL Research University, O.I.E. \u2013 Centre Observation, Impacts, Energy,  CS 10207 \u2013 06904 Sophia Antipolis cedex, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mossad","family":"El-Metwally","sequence":"additional","affiliation":[{"name":"Physics Department, Faculty of Science, Port Said University, Port Said 42526, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hosni","family":"Ghedira","sequence":"additional","affiliation":[{"name":"Masdar Institute, Research Center for Renewable Energy Mapping and Assessment, P.O. Box 54224 Abu Dhabi, UAE"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katja","family":"Hungershoefer","sequence":"additional","affiliation":[{"name":"Deutscher Wetterdienst, Offenbach 63067, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2916-2391","authenticated-orcid":false,"given":"Lucien","family":"Wald","sequence":"additional","affiliation":[{"name":"MINES ParisTech, PSL Research University, O.I.E. \u2013 Centre Observation, Impacts, Energy,  CS 10207 \u2013 06904 Sophia Antipolis cedex, France"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2015,7,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"4411","DOI":"10.1016\/j.enpol.2010.10.010","article-title":"The renewable energy targets of the Maghreb countries: Impact on electricity supply and conventional power markets","volume":"39","author":"Brand","year":"2011","journal-title":"Energy Policy"},{"key":"ref_2","unstructured":"Bryden, J., Riahi, L., and Zissler, R. 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