<br>Greetings =)<br>
<br> Could someone please help with projection issues?<br>
<br>
In trying to convert a raster image (gif) into a geotiff so that it can
be reprojected into mercator. I'm very new at this so have attempted to
read the docs carefully, but i have clearly made a mistake.<br>
<br>
Since i'm new, and am using a linux box I have found that gdal seems to
be the way to go, unless someone has a better suggestion (need command
line for automation).<br>
<br> The projection information for the
gif image is that it is a lambert conformal conic, but specifies a
tangent latitude, instead of the normal 1 or two latitudes of natural
origin. Here is the info and source information:<br>
<br> ########## SOURCE PROJECTION INFORMATION ###################<br> ## REF <a target="_blank" href="http://www.nws.noaa.gov/noaaport/html/icdtb48e.html">http://www.nws.noaa.gov/noaaport/html/icdtb48e.html</a> #<br> ############################################################<br> Eastern CONUS Lambert<br> Satellite: GOES East<br> Projection: Lambert Conformal<br> Tangent Latitude: 25.000N<br> Reference Longitude: 95.000W<br> Reference Grid: AWIPS Grid 211*<br> * The Dx, Dy grid increment (at 25 deg north) w as selected<br> so that the grid spacing would be exactly 80.0 00 k m at<br> 35 deg north<br>
<br> Lower Left: 16.369N 113.133W<br> Lower Right: 14.335N 65.091W<br> Upper Right: 57.289N 49.385W<br> Upper Left: 59.844N 123.044W<br>
<br> 1.0159Km @ 25.000N Visible<br> 5120x5120<br> ########################<br>
<br>
so not knowing what I am doing, and googling for all that i can find I
came up with the following means to set the projection, and reproject.<br>
<br> gdal_translate -of gtiff -a_srs '+proj=lcc +lat_ts=25 \<br> +lon_0=-95 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs' \<br> -a_ullr -123.044 59.844 -65.091 14.335 test.gif test.tif<br>
<br>
<br>
I'm guessing the 'lat_ts' parameter is incorrect, i just happened to
see it somewhere, but i have also tried setting the two lat parameters
to 25 as well, which did not work. I also tried using default lcc
projection information from ArcView for that projection to no avail.<br>
<br> Once finished my settings so far to convert to mercator are as follows<br> gdalwarp -t_srs '+proj=merc +a=6378137 \<br> +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 \<br> +units=m +nadgrids=@null +no_defs' test.tif mercator.tif<br>
<br>
I would really appreciate any help anyone can offer.. i've been banging
my head off the wall trying to figure this out, it has sort of become a
quest now... the issue seems to be using a tangent latitude instead of
the 1 or 2 latitudes of origin.<br>
<br> thanks much,<br>
<br> --buddy<br>
<br>
<br>
<br>
<br>
<br>
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