{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,21]],"date-time":"2026-05-21T03:39:55Z","timestamp":1779334795131,"version":"3.51.4"},"reference-count":29,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2015,9,21]],"date-time":"2015-09-21T00:00:00Z","timestamp":1442793600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>This paper presents the SPOT-4 (Take 5) experiment, aimed at providing time series of optical images simulating the repetitivity, the resolution and the large swath of Sentinel-2 images. The aim was to help users set up and test their applications and methods, before Sentinel-2 mission data become available. In 2016, when both Sentinel-2 satellites are operational, and for at least fifteen years, users will have access to high resolution time series of images systematically acquired every five days, over the whole Earth land surfaces. Thanks to Sentinel-2\u2019s high revisit frequency, a given surface should be observed without clouds at least once a month, except in the most cloudy periods and regions. In 2013, the Centre National d\u2019Etudes Spatiales (CNES) lowered the orbit altitude of SPOT-4, to place it on a five-day repeat cycle orbit for a duration of five months. This experiment started on 31 January 2013 and lasted until 19 June 2013. SPOT-4 images were acquired every fifth day, over 45 sites scattered in nearly all continents and covering very diverse biomes for various applications. Two ortho-rectified products were delivered for each acquired image that was not fully cloudy, expressed either as top of atmosphere reflectance (Level 1C) or as surface reflectance (Level 2A). An extensive validation campaign was held to check the performances of these products with regard to the multi-temporal registration, the quality of cloud masks, the accuracy of aerosol optical thickness estimates and the quality of surface reflectances. Despite high a priori geo-location errors, it was possible to register the images with an accuracy better than 0.5 pixels in the large majority of cases. Despite the lack of a blue band on the SPOT-4 satellite, the cloud and shadow detection yielded good results, while the aerosol optical thickness was measured with a root mean square error better than 0.06. The surface reflectances after atmospheric correction were compared with in situ data and other satellite data showing little bias and the standard deviation of surface reflectance errors in the range (0.01\u20130.02). The Take 5 experiment is being repeated in 2015 with the SPOT-5 satellite with an enhanced resolution.<\/jats:p>","DOI":"10.3390\/rs70912242","type":"journal-article","created":{"date-parts":[[2015,9,21]],"date-time":"2015-09-21T10:17:32Z","timestamp":1442830652000},"page":"12242-12264","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":75,"title":["SPOT-4 (Take 5): Simulation of Sentinel-2 Time Series on 45 Large Sites"],"prefix":"10.3390","volume":"7","author":[{"given":"Olivier","family":"Hagolle","sequence":"first","affiliation":[{"name":"Centre d\u2019\u00e9tudes Spatiales de la Biosph\u00e8re, CESBIO Unite mixte Universit\u00e9 de Toulouse-CNES-CNRS-IRD, 18 avenue E.Belin, 31401 Toulouse Cedex 9, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sylvia","family":"Sylvander","sequence":"additional","affiliation":[{"name":"CNES, 18 avenue Edouard Belin 31401 Toulouse Cedex 9, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mireille","family":"Huc","sequence":"additional","affiliation":[{"name":"Centre d\u2019\u00e9tudes Spatiales de la Biosph\u00e8re, CESBIO Unite mixte Universit\u00e9 de Toulouse-CNES-CNRS-IRD, 18 avenue E.Belin, 31401 Toulouse Cedex 9, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Martin","family":"Claverie","sequence":"additional","affiliation":[{"name":"NASA GSCF, Code 619, Bldg 32, N149-6, Greenbelt, MD 20771, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8830-6191","authenticated-orcid":false,"given":"Dominique","family":"Clesse","sequence":"additional","affiliation":[{"name":"Capgemini Technology Services, 109 avenue Eisenhower - BP 53655, 31036 Toulouse Cedex 1, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"C\u00e9cile","family":"Dechoz","sequence":"additional","affiliation":[{"name":"CNES, 18 avenue Edouard Belin 31401 Toulouse Cedex 9, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vincent","family":"Lonjou","sequence":"additional","affiliation":[{"name":"CNES, 18 avenue Edouard Belin 31401 Toulouse Cedex 9, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vincent","family":"Poulain","sequence":"additional","affiliation":[{"name":"Thales Services, 3 avenue de l\u2019Europe - Bat. D, 31400 Toulouse, France"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2015,9,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1016\/j.rse.2011.11.026","article-title":"Sentinel-2: ESA\u2019s Optical High-Resolution Mission for GMES Operational Services","volume":"120","author":"Drusch","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1080\/0143116031000115265","article-title":"VEGETATION\/SPOT: An operational mission for the Earth monitoring; presentation of new standard products","volume":"25","author":"Maisongrande","year":"2004","journal-title":"Int. J. Remote Sens."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Tinel, C., Fontannaz, D., de Boissezon, H., Grizonnet, M., and Michel, J. (2012). The ORFEO acompaniment program and ORFEO ToolBox. IGARSS.","DOI":"10.1109\/IGARSS.2012.6352026"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2668","DOI":"10.3390\/rs70302668","article-title":"A multi-temporal and multi-spectral method to estimate aerosol optical thickness over land, for the atmospheric correction of FormoSat-2, LandSat, VEN\u00b5S and Sentinel-2 images","volume":"7","author":"Hagolle","year":"2015","journal-title":"Remote Sens."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Bignalet-Cazalet, F., Baillarin, S., Greslou, D., and Panem, C. (2010). Automatic and generic mosaicing of satellite images. IGARSS.","DOI":"10.1109\/IGARSS.2010.5650102"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Baillarin, S., Gigord, P., and Hagolle, O. (2008). Automatic registration of optical images, a stake for future missions: Application to ortho-rectification, time series and mosaic products. IGARSS.","DOI":"10.1109\/IGARSS.2008.4779194"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1689","DOI":"10.1016\/j.rse.2007.08.016","article-title":"Correction of aerosol effects on multi-temporal images acquired with constant viewing angles: Application to Formosat-2 images","volume":"112","author":"Hagolle","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1747","DOI":"10.1016\/j.rse.2010.03.002","article-title":"A multi-temporal method for cloud detection, applied to Formosat-2, VEN\u03bcS, Landsat and Sentinel-2 images","volume":"114","author":"Hagolle","year":"2010","journal-title":"Remote Sens. Environ."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"205","DOI":"10.1016\/0924-2716(91)90054-Y","article-title":"SPOT 4: A new generation of SPOT satellites","volume":"46","author":"Arnaud","year":"1991","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_10","unstructured":"Kubik, P., Breton, E., Meygret, A., Cabrieres, B., Hazane, P., and Leger, D. (1998). SPOT4 HRVIR first in-flight image quality results. Proc. SPIE."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Meygret, A., Dinguirard, M.C., Henry, P.J., Poutier, L., Lafont, S., and Hazane, P. (1997). SPOT Histogram data base. Proc. SPIE.","DOI":"10.1117\/12.265447"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Moy, J.P., Hugon, X., Chabbal, J., De Cachard, J., Lenoble, C., Mollaret, D., Villard, M., and Villotitch, B. (1989). 3000 In Ga As Photodiode Multiplexed Linear Array For The Spot 4 S.W.I.R. Channel. Proc. SPIE.","DOI":"10.1117\/12.960659"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2833","DOI":"10.1080\/01431160310001618392","article-title":"Photogrammetric exploitation of IKONOS imagery for mapping applications","volume":"25","author":"Tao","year":"2004","journal-title":"Int. J. Remote Sens."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1016\/j.rse.2004.11.005","article-title":"Surface motion of mountain glaciers derived from satellite optical imagery","volume":"95","author":"Berthier","year":"2005","journal-title":"Remote Sens. Environ."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"48","DOI":"10.1016\/j.isprsjprs.2014.03.002","article-title":"Measurement of ground displacement from optical satellite image correlation using the free open-source software MicMac","volume":"100","author":"Rosu","year":"2015","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2972","DOI":"10.1109\/TGRS.2011.2122337","article-title":"Geolocation Assessment of MERIS GlobCover Orthorectified Products","volume":"49","author":"Bicheron","year":"2011","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Meygret, A. (2005). Absolute calibration: From SPOT1 to SPOT5. Proc. SPIE.","DOI":"10.1117\/12.613855"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1016\/j.rse.2011.10.028","article-title":"Object-based cloud and cloud shadow detection in Landsat imagery","volume":"118","author":"Zhu","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/S0034-4257(98)00031-5","article-title":"AERONET\u2014A federated instrument network and data archive for aerosol characterization","volume":"66","author":"Holben","year":"1998","journal-title":"Remote Sens. Environ."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1016\/0034-4257(92)90080-4","article-title":"SPOT calibration at the La Crau test site (France)","volume":"41","author":"Santer","year":"1992","journal-title":"Remote Sens. Environ."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Meygret, A., Santer, R.P., and Berthelot, B. (2011). ROSAS: A robotic station for atmosphere and surface characterization dedicated to on-orbit calibration. Proc. SPIE.","DOI":"10.1117\/12.892759"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"20455","DOI":"10.1029\/92JD01411","article-title":"A bidirectional reflectance model of the Earth\u2019s surface for the correction of remote sensing data","volume":"97","author":"Roujean","year":"1992","journal-title":"J. Geophys. Res.: Atmos."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Claverie, M., Vermote, E.F., Franch, B., and Masek, J.G. (2014). Evaluation of the Landsat-5 TM and Landsat-7 ETM+ surface reflectance products. Remote Sens. Environ., in press.","DOI":"10.1016\/j.rse.2015.08.030"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"898","DOI":"10.1109\/TGRS.2008.2005977","article-title":"Towards a generalized approach for correction of the BRDF effect in MODIS directional reflectances","volume":"47","author":"Vermote","year":"2009","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"11182","DOI":"10.3390\/rs61111182","article-title":"A life-size and near real-time test of irrigation scheduling with a Sentinel-2 Like Time Series (SPOT4-Take5) in Morocco","volume":"6","author":"Toumi","year":"2014","journal-title":"Remote Sens."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"5815","DOI":"10.3390\/rs6065815","article-title":"Monitoring of irrigation schemes by remote sensing: Phenology versus retrieval of biophysical variables","volume":"6","author":"Akdim","year":"2014","journal-title":"Remote Sens."},{"key":"ref_27","first-page":"23","article-title":"First assessment on the potential of Sentinel-2 data for land area monitoring in Southeast Asian conditions","volume":"15","author":"Miettinen","year":"2015","journal-title":"Asian J. Geoinf."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"D13205","DOI":"10.1029\/2008JD011115","article-title":"Aerosol analysis and forecast in the European Centre for Medium-Range Weather Forecasts Integrated Forecast System: 2. Data assimilation","volume":"114","author":"Benedetti","year":"2009","journal-title":"J. Geophys. Res."},{"key":"ref_29","unstructured":"Suarez, M.J., Rienecker, M.M., Todling, R., Bacmeister, J., Takacs, L., Liu, H.C., Gu, W., Sienkiewicz, M., Koster, R.D., and Gelaro, R. (2008). The GEOS-5 Data Assimilation System, Documentation of Versions 5.0. 1, 5.1. 0, and 5.2. 0."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/7\/9\/12242\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T20:48:57Z","timestamp":1760215737000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/7\/9\/12242"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,9,21]]},"references-count":29,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2015,9]]}},"alternative-id":["rs70912242"],"URL":"https:\/\/doi.org\/10.3390\/rs70912242","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2015,9,21]]}}}