{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,11]],"date-time":"2026-06-11T21:33:42Z","timestamp":1781213622919,"version":"3.54.1"},"reference-count":28,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2009,8,3]],"date-time":"2009-08-03T00:00:00Z","timestamp":1249257600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Global land cover is one of the essential terrestrial baseline datasets available for ecosystem modeling, however uncertainty remains an issue. Tools such as Google Earth offer enormous potential for land cover validation. With an ever increasing amount of very fine spatial resolution images (up to 50 cm \u00d7 50 cm) available on Google Earth, it is becoming possible for every Internet user (including non remote sensing experts) to distinguish land cover features with a high degree of reliability. Such an approach is inexpensive and allows Internet users from any region of the world to get involved in this global validation exercise. The Geo-Wiki Project is a global network of volunteers who wish to help improve the quality of global land cover maps. Since large differences occur between existing global land cover maps, current ecosystem and land-use science lacks crucial accurate data (e.g., to determine the potential of additional agricultural land available to grow crops in Africa), volunteers are asked to review hotspot maps of global land cover disagreement and determine, based on what they actually see in Google Earth and their local knowledge, if the land cover maps are correct or incorrect. Their input is recorded in a database, along with uploaded photos, to be used in the future for the creation of a new and improved hybrid global land cover map.<\/jats:p>","DOI":"10.3390\/rs1030345","type":"journal-article","created":{"date-parts":[[2009,8,3]],"date-time":"2009-08-03T13:05:58Z","timestamp":1249304758000},"page":"345-354","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":274,"title":["Geo-Wiki.Org: The Use of Crowdsourcing to Improve Global Land Cover"],"prefix":"10.3390","volume":"1","author":[{"given":"Steffen","family":"Fritz","sequence":"first","affiliation":[{"name":"Forestry Program, International Institute for Applied Systems Analysis, Laxenburg, Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ian","family":"McCallum","sequence":"additional","affiliation":[{"name":"Forestry Program, International Institute for Applied Systems Analysis, Laxenburg, Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7093-443X","authenticated-orcid":false,"given":"Christian","family":"Schill","sequence":"additional","affiliation":[{"name":"Department of Remote Sensing and Landscape Information Systems (FeLis), University of Freiburg, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christoph","family":"Perger","sequence":"additional","affiliation":[{"name":"University of Applied Sciences Wiener Neustadt for Business and Engineering Ltd., Wiener Neustadt, Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Roland","family":"Grillmayer","sequence":"additional","affiliation":[{"name":"University of Applied Sciences Wiener Neustadt for Business and Engineering Ltd., Wiener Neustadt, Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Fr\u00e9d\u00e9ric","family":"Achard","sequence":"additional","affiliation":[{"name":"Institute for Environment and Sustainability, Joint Research Centre of the European Commission, Ispra, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Florian","family":"Kraxner","sequence":"additional","affiliation":[{"name":"Forestry Program, International Institute for Applied Systems Analysis, Laxenburg, Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael","family":"Obersteiner","sequence":"additional","affiliation":[{"name":"Forestry Program, International Institute for Applied Systems Analysis, Laxenburg, Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2009,8,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1111\/j.1467-8306.2007.00534.x","article-title":"Sharing geographic information: an assessment of the geospatial one-stop","volume":"97","author":"Goodchild","year":"2007","journal-title":"Ann. Assn. Amer. Geogr."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1007\/s10708-008-9188-y","article-title":"The credibility of volunteered geographic information","volume":"72","author":"Flanagin","year":"2008","journal-title":"GeoJournal"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.compenvurbsys.2007.12.001","article-title":"The wikification of GIS and its consequences: or Angelina Jolie\u2019s new tattoo and the future of GIS","volume":"32","author":"Sui","year":"2008","journal-title":"Comp. Env. Urb. Sys."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1007\/s10708-007-9111-y","article-title":"Citizens as sensors: The world of volunteered geography","volume":"69","author":"Goodchild","year":"2007","journal-title":"GeoJournal"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Hudson-Smith, A., Batty, M., Crooks, A., and Milton, R. (2009). Mapping for the masses: accessing web 2.0 through crowdsourcing. Soc. Sci. Comput. Rev.","DOI":"10.1177\/0894439309332299"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"229","DOI":"10.1007\/s10708-008-9182-4","article-title":"A trust and reputation model for filtering and classifying knowledge about urban growth","volume":"72","author":"Bishr","year":"2008","journal-title":"GeoJournal"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"907","DOI":"10.1068\/b2751t","article-title":"Public participation, GIS, and cyberdemocracy: evaluating on-line spatial decision support systems","volume":"28","author":"Carver","year":"2001","journal-title":"Environ. Plan. B-Plan. Design"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"2011","DOI":"10.1111\/j.1749-8198.2008.00167.x","article-title":"Web mapping 2.0: the neogeography of the GeoWeb","volume":"2","author":"Haklay","year":"2008","journal-title":"Geogr. Compass"},{"key":"ref_9","first-page":"28","article-title":"The beginning and end of neogeography","volume":"7","author":"Walsh","year":"2008","journal-title":"GEO: connexion"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1007\/s10708-008-9190-4","article-title":"Commentary: whither VGI?","volume":"72","author":"Goodchild","year":"2008","journal-title":"GeoJournal"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1007\/s10708-008-9184-2","article-title":"The role of facilitated volunteered geographic information in the landscape planning and site design process","volume":"72","author":"Seeger","year":"2008","journal-title":"GeoJournal"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"7973","DOI":"10.3390\/s8127973","article-title":"Horizontal positional accuracy of google earth\u2019s high-resolution imagery archive","volume":"8","author":"Potere","year":"2008","journal-title":"Sensors"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"776","DOI":"10.1038\/439776a","article-title":"The web-wide world","volume":"439","author":"Butler","year":"2006","journal-title":"Nature"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1016\/j.isprsjprs.2008.09.004","article-title":"Pan-European forest\/non-forest mapping with Landsat ETM+ and CORINE Land Cover 2000 data","volume":"64","author":"Pekkarinen","year":"2009","journal-title":"ISPRS J. Photogramm."},{"key":"ref_15","unstructured":"Defourny, P.P., Schouten, L., Bartalev, S., Bontemps, S.P., Caccetta, P., de Wit, A.J. W.P., Di Bella, C.P., G\u00e9rard, B.P., Giri, C.P., Gond, V.P., Hazeu, G.W.P., Heinimann, A.P., Herold, M.P., Knoops, J.P., Jaffrain, G.P., Latifovic, R.P., Lin, H.P., Mayaux, P.P., M\u00fccher, C.A.P., Nonguierma, A.P., Stibig, H.P., Van Bogaert, E.P., Vancutsem, C.P., Bicheron, P.P., Leroy, M.P., and Arino, O.P. Available online: http:\/\/dup.esrin.esa.it\/files\/project\/131-176-149-30_2009512134035.pdf."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1740","DOI":"10.1109\/TGRS.2006.874750","article-title":"A method to compare and improve land cover datasets: application to the GLC-2000 and MODIS land cover products","volume":"44","author":"See","year":"2006","journal-title":"IEEE Trans. Geosci. Remot. Sen."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1959","DOI":"10.1080\/01431160412331291297","article-title":"GLC2000: a new approach to global land cover mapping from earth observation data","volume":"26","author":"Belward","year":"2005","journal-title":"Int. J. Remote. Sens."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"287","DOI":"10.1016\/S0034-4257(02)00078-0","article-title":"Global land cover mapping from MODIS: algorithms and early results","volume":"83","author":"Friedl","year":"2002","journal-title":"Remote. Sens. Environ."},{"key":"ref_19","unstructured":"Arino, O., Bicheron, P., Achard, F., Latham, J., Witt, R., and Weber, J.L. Available online: http:\/\/www.esa.int\/esapub\/bulletin\/bulletin136\/bul136d_arino.pdf."},{"key":"ref_20","first-page":"246","article-title":"A spatial comparison of four satellite derived 1 km global land cover datasets","volume":"8","author":"McCallum","year":"2006","journal-title":"Int. J. Applearth. Obs. Geonif."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1057","DOI":"10.1111\/j.1365-2486.2007.01519.x","article-title":"Identifying and quantifying uncertainty and spatial disagreement in the comparison of Global Land Cover for different applications","volume":"14","author":"Fritz","year":"2008","journal-title":"Global Change Biolo."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Iwao, K., Nishida, K., Kinoshita, T., and Yamagata, Y. (2006). Validating land cover maps with Degree Confluence Project information. Geophys. Res. Lett., 33.","DOI":"10.1029\/2006GL027768"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"731","DOI":"10.1111\/j.1529-8817.2003.00774.x","article-title":"A land cover map of South America","volume":"10","author":"Eva","year":"2004","journal-title":"Glob. Change Biol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"861","DOI":"10.1111\/j.1365-2699.2004.01073.x","article-title":"A new land-cover map of Africa for the year 2000","volume":"31","author":"Mayaux","year":"2004","journal-title":"J. Biogeogr."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1728","DOI":"10.1109\/TGRS.2006.864370","article-title":"Validation of the global land cover 2000 map","volume":"44","author":"Mayaux","year":"2006","journal-title":"IEEE Trans. Geosci. Remot. Sen."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Giles, J. (2006). Wikipedia rival calls in the experts. Nature., 443.","DOI":"10.1038\/443493a"},{"key":"ref_27","unstructured":"Ridder, R. (2007). Options and recommendations for a global remote sensing survey of forests. Forest Resources Assessment, Food and Agriculture Organization of the United Nations."},{"key":"ref_28","unstructured":"Eva, H.D., Carboni, S., Achard, F., Stach, N., Durieux, L., Faure, J.-F., and Mollicone, D. Monitoring forest areas from continental to territorial levels using a sample of medium spatial resolution satellite imagery, ISPRS International Journal of Photogrammetry & Remote Sensing, (in press)."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/1\/3\/345\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T22:10:52Z","timestamp":1760220652000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/1\/3\/345"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2009,8,3]]},"references-count":28,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2009,9]]}},"alternative-id":["rs1030345"],"URL":"https:\/\/doi.org\/10.3390\/rs1030345","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2009,8,3]]}}}