Differences

This shows you the differences between two versions of the page.

--- lovergine:geotricks [2011/04/09 10:14]
frankie created
+++ lovergine:geotricks [2011/05/26 12:37] (current)
frankie
@@ Line 1: / Line 1: @@
 ====== Geotricks ======
-This page is dedicated to sparse and casual tricks with GFOSS.
+This page is dedicated to sparse and casual tricks with some common GFOSS tools.
 ===== Merging multiple Geotiff bands =====
+This command works with relatively recent [[http://gdal.osgeo.org/|Gdal]] versions:
 <code>
 gdal_merge.py -o multiband.tif -separate band1.tif band2.tif band3.tif
 </code>
+===== Changing raster resolution in Grass  =====
+Just use the builtin computing region facility, it will use a nearest neighbor interpolation for this purpose:
+<code>
+g.region rast=original_map -p
+g.region res=<new>
+r.mapcalc "new_map=original_map"
+</code>
+A similar trick can be used to cut a portion of the original map, apply a mask, etc. A more capable module for those applications is ''r.resamp.interp'' which can be used instead of ''r.mapcalc'' to peform also bilinear and bicubic interpolation for the assigned raster grid. A nearest neighbor interpolation can also be performed by the ''r.resample'' module as well.
+===== WMS/WFS at PCN =====
+See [[WMS at PCN|here]] for details about using GRASS with national service at PCN.
+===== Precision grid =====
+[[http://lists.maptools.org/pipermail/proj/2011-April/005628.html|This]] is a very interesting thread about creating proj NTv2 precision grids starting from national precision grids in other formats, up to about 1:2000 scale and more.

Earth Observation Group Wiki

User Tools

Site Tools

Differences

Page Tools