Changes between Version 110 and Version 111 of WKTRasterTutorial01
- Timestamp:
- 02/17/11 06:26:48 (14 years ago)
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WKTRasterTutorial01
v110 v111 34 34 * The first dataset is a point shapefile of 814 caribou observations done by airplane in the northern part of the province of Quebec by the provincial ministry of natural ressources between 1999 and 2005. We do not provide this file. We will show later in the tutorial how you can easily produce a similar random point cover. You can also use your set of point. 35 35 36 * The second dataset is a series of 13 SRTM elevation rasters covering most of the province of Quebec. These free rasters, available on the web, are 6000x6000 pixels each, have a pixel size of about 60 x 90 meters and weight a total of 900 MB once unzipped. There are many versions of SRTM. We choose the one at ftp:// srtm.csi.cgiar.org/SRTM_v41/SRTM_Data_GeoTIFF/ . You do not have to download the same files we used. Just download ten of them in the area of your choice. You can find a pretty good description of this dataset in Wikipedia (http://en.wikipedia.org/wiki/SRTM).36 * The second dataset is a series of 13 SRTM elevation rasters covering most of the province of Quebec. These free rasters, available on the web, are 6000x6000 pixels each, have a pixel size of about 60 x 90 meters and weight a total of 900 MB once unzipped. There are many versions of SRTM. We choose the one at ftp://ftp.ciat.cgiar.org/DAPA/edarague/P03_30x30_cut/TIFFs/ . You do not have to download the same files we used. Just download ten of them in the area of your choice. You can find a pretty good description of this dataset in Wikipedia (http://en.wikipedia.org/wiki/SRTM). 37 37 38 38 We will import the shapefile and the raster coverage into PostGIS, create buffers around each point and then intersect those buffers with the elevation coverage in order to get a weighted mean elevation for each buffer. We will have a graphical look at the different results along the way using OpenJUMP.