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<TITLE>Re: [Gdal-dev] changing EPSG >> pixel resolution -- more clearly</TITLE>
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<FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>Mattia -<BR>
<BR>
Generally, no, it’s not doable, at least not while maintaining unprojected data. A degree of latitude and a degree of longitude are not the same size, and their sizes vary depending on where on the Earth they are located. One degree of longitude is a different size (in meters) at the northern edge of your image than it is on the southern edge.<BR>
<BR>
If you need to measure in meters you should project your image from geographic coordinates to a projected coordinate system. Your image covers a fairly large area so you should think carefully about what projection is best for your needs.<BR>
<BR>
Or you could revisit your requirement; why you need an image with units in meters?<BR>
<BR>
- Ed<BR>
<BR>
-- <BR>
Ed McNierney<BR>
President and Chief Mapmaker<BR>
Maps a la carte, Inc. / TopoZone.com<BR>
73 Princeton Street, Suite 305<BR>
North Chelmsford, MA 01863<BR>
Phone: (978) 251-4242<BR>
Fax: (978) 251-1396<BR>
ed@topozone.com<BR>
<BR>
<HR ALIGN=CENTER SIZE="3" WIDTH="95%"><B>From: </B>mattia <mattia.parigiani@gmail.com><BR>
<B>Date: </B>Fri, 4 May 2007 17:51:41 +0200<BR>
<B>To: </B>gdal-dev <gdal-dev@lists.maptools.org><BR>
<B>Subject: </B>[Gdal-dev] changing EPSG >> pixel resolution -- more clearly<BR>
<BR>
Maybe I wasnt clear enough in my previous email:<BR>
<BR>
My gdalinfo output on the new geotiff is:<BR>
<BR>
rasdaman@mattia-desktop:/opt/rasdaman/local$ gdalinfo 250mGrey20070115065625.tif<BR>
Driver: GTiff/GeoTIFF<BR>
Size is 886, 883<BR>
Coordinate System is:<BR>
GEOGCS["WGS 84",<BR>
DATUM["WGS_1984",<BR>
SPHEROID["WGS 84",6378137,298.2572235629972,<BR>
AUTHORITY["EPSG","7030"]], <BR>
AUTHORITY["EPSG","6326"]],<BR>
PRIMEM["Greenwich",0],<BR>
UNIT["degree",0.0174532925199433],<BR>
AUTHORITY["EPSG","4326"]]<BR>
Origin = (75.968700 ,53.448282)<BR>
Pixel Size = (0.03237320,-0.03237320)<BR>
Metadata:<BR>
TIFFTAG_XRESOLUTION=100<BR>
TIFFTAG_YRESOLUTION=100<BR>
Corner Coordinates:<BR>
Upper Left ( 75.9686998, 53.4482818) ( 75d58'7.32"E, 53d26' 53.81"N)<BR>
Lower Left ( 75.9686998, 24.8627462) ( 75d58'7.32"E, 24d51'45.89"N)<BR>
Upper Right ( 104.6513550, 53.4482818) (104d39'4.88"E, 53d26'53.81"N)<BR>
Lower Right ( 104.6513550 , 24.8627462) (104d39'4.88"E, 24d51'45.89"N)<BR>
Center ( 90.3100274, 39.1555140) ( 90d18'36.10"E, 39d 9'19.85"N)<BR>
Band 1 Block=886x1 Type=Byte, ColorInterp=Gray<BR>
rasdaman@mattia-desktop :/opt/rasdaman/local$<BR>
<BR>
<BR>
I dont want degrees in Pixel Size = (0.03237320,-0.03237320) but I require meters... Is this possibly doable??<BR>
<BR>
Thanks again<BR>
<BR>
-- <BR>
Mattia<BR>
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