Changes between Version 108 and Version 109 of WKTRasterTutorial01


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Timestamp:
01/17/11 13:13:05 (14 years ago)
Author:
pracine
Comment:

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  • WKTRasterTutorial01

    v108 v109  
    315315The buffers have and oval shape because they are displayed in a non-projected spatial reference system (WGS 84) to fit with the raster layer. In the database they were created in a projected coordinate system (NAD 83/Quebec Lambert) and are truly circle all of equal area. You can observe that southern buffers, again because they are displayed in a non-projected spatial reference system, are smaller (less wide) than the northern ones. If we would display everything in NAD 83/Quebec Lambert, they would all be of the same circle shape. But we can't do this because our raster are in WGS 84 and PostGIS do not support raster reprojection yet.
    316316 
    317 We then reproject our buffers to WGS 84 so we can intersect them with our raster coverage:
     317We then reproject our buffers to WGS 84 as a new table in order to intersect them with our raster coverage:
    318318
    319319{{{
    … …  
    323323}}}
    324324
    325 Again the same kind of query to display them in OpenJUMP and confirm that they overlap with the raster coverage and see that now they are a bit squashed:
     325Again the same kind of query to display them in OpenJUMP and confirm that they overlap with the raster coverage without having to reproject them. We can see that now they are a bit squashed:
    326326
    327327{{{