on obtient une archive contenant 4 fichiers (ex. readme.txt\u00a0; srtm_41_05.hdr\u00a0; srtm_41_05.tif\u00a0; srtm_41_05.tfw)<\/p>\n
Mosa\u00efque\u00a0:<\/h3>\n
D\u00e9placer tous les fichiers dans un seul r\u00e9pertoire. Plus d\u2019options GDAL sur\u00a0http:\/\/www.gdal.org\/index.html<\/a><\/p>\n Plus d\u2019options GDAL sur\u00a0http:\/\/www.gdal.org\/index.html<\/a><\/p>\n Plus d\u2019options GDAL sur\u00a0http:\/\/www.gdal.org\/index.html<\/a><\/p>\n","protected":false},"excerpt":{"rendered":" Cette proc\u00e9dure d\u00e9crit la m\u00e9thode pour t\u00e9l\u00e9charger et pr\u00e9traiter les dalles SRTM v4. T\u00e9l\u00e9chargement\u00a0: se connecter sur le serveur\u00a0CGIAR\u00a0dans la partie SRTM Data Search and Download et choisir une ou plusieurs dalles de 5\u00b0x5\u00b0 on obtient une archive contenant 4 fichiers (ex. readme.txt\u00a0; srtm_41_05.hdr\u00a0; srtm_41_05.tif\u00a0; srtm_41_05.tfw) Mosa\u00efque\u00a0: D\u00e9placer tous les fichiers dans un seul r\u00e9pertoire. … Continue reading “Traiter les dalles SRTM avec GDAL”<\/span><\/a><\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12,7],"tags":[],"class_list":["post-118","post","type-post","status-publish","format-standard","hentry","category-gdal-ogr","category-geo-traitements"],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=\/wp\/v2\/posts\/118","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=118"}],"version-history":[{"count":1,"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=\/wp\/v2\/posts\/118\/revisions"}],"predecessor-version":[{"id":119,"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=\/wp\/v2\/posts\/118\/revisions\/119"}],"wp:attachment":[{"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=118"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=118"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sigeo.cerege.fr\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=118"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\nPuis lancer la commande\u00a0:
\ngdal_merge.py -n -32768 -o out_filename input_files<\/code><\/p>\n![\"-\"](\"https:\/\/sigeo.cerege.fr\/squelettes-dist\/puce.gif\")
\u00a0n -32768\u00a0: pour fixer les valeurs nodata
\nout_filename\u00a0: nom du fichier en sorite
\ninput_files\u00a0: liste de fichiers en entr\u00e9e<\/p>\nD\u00e9coupage d\u2019une zone<\/h3>\n
gdal_translate -projwin ulx uly llx lly) src_dataset dst_dataset<\/code>
\nulx uly llx lly sont les coordonn\u00e9es projet\u00e9es de la zone \u00e0 d\u00e9couper, ex. en WGS84 sur la Cr\u00eate 23 36 27 34
\nsrc_dataset\u00a0: fichier en entr\u00e9e
\ndst_dataset\u00a0: fichier en sortie<\/p>\nOmbrage (ou estompage)<\/h3>\n
gdaldem hillshade -s 111120 input_dem output_hillshade<\/code><\/p>\n\u00a0s 111120\u00a0: ratio pour les unit\u00e9s verticales dans le cas o\u00f9 les coordonn\u00e9es sont en degr\u00e9s (e.g. Lat\/Long WGS84) et les altitudes en m\u00e8tres.<\/p>\n