Using R to change raster projection
<p>I'm trying to change raster projection using <code>R</code> and the <code>raster</code> package. The input raster projection is Lambert Azimuthal; the parameters are here:</p>

<pre><code>Coordinate System:
Lambert_Azimuthal_Equal_Area
False_Easting: 4321000,000000
False_Northing: 3210000,000000
Central_Meridian: 10,000000
Latitude_Of_Origin: 52,000000
GCS_ETRS_1989
Datum: D_ETRS_1989
Prime Meridian: 0


PROJCS
 ["ETRS_1989_LAEA",
   GEOGCS ["GCS_ETRS_1989",
           DATUM ["D_ETRS_1989",
                  SPHEROID ["GRS_1980",6378137.0,298.257222101]],
           PRIMEM["Greenwich",0.0],
          UNIT["Degree",0.0174532925199433]],
   PROJECTION["Lambert_Azimuthal_Equal_Area"],
   PARAMETER["False_Easting",4321000.0],
   PARAMETER["False_Northing",3210000.0],
   PARAMETER["Central_Meridian",10.0],
   PARAMETER["Latitude_Of_Origin",52.0],
   UNIT["Meter",1.0]]
</code></pre>

<p>I need to convert them to simple rasters in ESRI ASCII format, using longitude and latitude coordinates, with a Mercator-style projection, with a cell size of 0.1 degrees (I hope I explain myself well enough, because I don't have enough GIS skills, sorry). What I need are rasters in format <code>.ASC</code> where each value of the raster corresponds to a single cell of size <code>N x N</code>, where <code>N</code> is in degrees (e.g. 0.1 degrees), and the raster coordinates are in longitude/latitude.</p>

<p>I tried to use <code>raster</code> library in <code>R</code>, and follow examples found for the <code>projectRaster</code> function. But after many attempts using many several parameters, I wasn't be able to make it correctly. I think I'm not using the correct parameters for projection, datum, or something like this.</p>

<p>Here's what I tried. I load the raster in R, then I set its projection using:</p>

<pre><code>&gt;crs(r)&lt;-"+proj=laea +lat_1=52 +lon_0=-10 +ellps=GRS80"
</code></pre>

<p>Then I define the output projection and I try the conversion and save:</p>

<pre><code>&gt;newproj &lt;- "+proj=lonlat +lat_1=52 +lon_0=-10 +ellps=WGS84"
&gt;pr2 &lt;- projectRaster(r, crs=newproj, res=0.1)
&gt;writeRaster(pr2, "newraster.asc", overwrite=TRUE)
</code></pre>

<p>No error messages, but resulting raster is not correctly projected (country borders don’t match, countries are slightly distorted).</p>

<p>Thanks for any help!</p>