Difference between revisions of "Meteorology"

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* Work in progress: {{AddonCmd|d.barb}}: Displays wind barbs or variable length straw diagrams given either two raster maps, or vector point data. Like {{cmd|d.rast.arrow}}, input data is given as magnitude and direction, unlike ''d.rast.arrow'' you can also feed it u,v component data.  (Hamish), See also [http://casoilresource.lawr.ucdavis.edu/drupal/node/989 Visualizing Terrain Surface Indicies with Scaled Arrows].
* Work in progress: {{AddonCmd|d.barb}}: Displays wind barbs or variable length straw diagrams given either two raster maps, or vector point data. Like {{cmd|d.rast.arrow}}, input data is given as magnitude and direction, unlike ''d.rast.arrow'' you can also feed it u,v component data.  (Hamish), See also [http://casoilresource.lawr.ucdavis.edu/drupal/node/989 Visualizing Terrain Surface Indicies with Scaled Arrows].


<center>
[[Image:D_rast_arrow_magnitude.png|thumb|right|200px|d.rast.arrow at work]]
[[Image:D_rast_arrow_magnitude.png|thumb|right|200px|d.rast.arrow at work]]
</center>


* {{cmd|r.in.gdal}} - useful for importing raster data from [http://www.gdal.org/formats_list.html very many source data formats].
* {{cmd|r.in.gdal}} - useful for importing raster data from [http://www.gdal.org/formats_list.html very many source data formats].

Revision as of 09:14, 19 June 2014

Meteorology

GRASS used together with R-stats provides a powerful toolset to analyse meteorological time series and to perform spatio-temporal interpolation.



d.rast.arrow at work
  • r.series - useful for time series analysis of raster data.
  • v.surf.rst - useful for 2D spline interpolation between sparse data points.


Conventions

Wind meteo data usually follow a convention different from the GRASS one. First, the wind direction expresses the direction which wind blows FROM and not TO. Second, the convention on directions differs from the one adopted by GRASS (for aspect, flow direction, etc.).