<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Frank, I did that, and now gdalinfo shows the gdal_translate output GeoTiff does have the same values as those of the GeoTiff with the desired UTM projection for PROJCS to AUTHORITY</div><div><div>Coordinate System is:</div><div>PROJCS["NAD83 / UTM zone 18N",</div><div> GEOGCS["NAD83",</div><div> DATUM["North_American_Datum_1983",</div><div> SPHEROID["GRS 1980",6378137,298.2572221010002,</div><div> AUTHORITY["EPSG","7019"]],</div><div> AUTHORITY["EPSG","6269"]],</div><div> PRIMEM["Greenwich",0],</div><div> UNIT["degree",0.0174532925199433],</div><div> AUTHORITY["EPSG","4269"]],</div><div> PROJECTION["Transverse_Mercator"],</div><div> PARAMETER["latitude_of_origin",0],</div><div> PARAMETER["central_meridian",-75],</div><div> PARAMETER["scale_factor",0.9996],</div><div> PARAMETER["false_easting",500000],</div><div> PARAMETER["false_northing",0],</div><div> UNIT["metre",1,</div><div> AUTHORITY["EPSG","9001"]],</div><div> AUTHORITY["EPSG","26918"]]</div></div><div><br></div><div>then gdalinfo shows on the next 2 lines of its report that while the GeoTiff in the desired UTM projection has reasonable values for Origin and Pixel size, the gdal_translate output GeoTiff apparently still has its Origin and Pixel size values in latitude and longitude, which is apparently preventing Qgis from displaying the gdal_translate output GeoTiff. </div><div>gdalinfo report for input GeoTiff</div><div><div>Origin = (271500.000000000000000,4335000.000000000000000)</div><div>Pixel Size = (38.385826771653548,-38.385826771653548)</div></div><div><br></div><div>gdalinfo report for gdal_translate output GeoTiff</div><div><div>Origin = (-78.000555555559998,40.000555555555515)</div><div>Pixel Size = (0.000092592592593,-0.000092592592593)</div></div><div>Is there another necessary step? Greg</div><br><div><div>On Jul 3, 2010, at 10:10 AM, Frank Warmerdam wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>Greg Coats wrote:<br><blockquote type="cite">gdal_translate -a_srs provides for the output file to be in a different projection than the input file.<br></blockquote><blockquote type="cite">What is the syntax for telling gdal_translate -a_srs to use the projection shown by gdalinfo to be used in the GeoTiff below, which is NAD 1983, UTM Zone 18N?<br></blockquote><br>Greg,<br><br>One approach is to just copy the coordinate system portion, as<br>below into a text file, perhaps "desired.wkt" and then<br>do:<br><br>gdal_translate -a_srs desired.wkt in.tif out.tif<br><br>PROJCS["NAD83 / UTM zone 18N",<br> GEOGCS["NAD83",<br> DATUM["North_American_Datum_1983",<br> SPHEROID["GRS 1980",6378137,298.2572221010002,<br> AUTHORITY["EPSG","7019"]],<br> AUTHORITY["EPSG","6269"]],<br> PRIMEM["Greenwich",0],<br> UNIT["degree",0.0174532925199433],<br> AUTHORITY["EPSG","4269"]],<br> PROJECTION["Transverse_Mercator"],<br> PARAMETER["latitude_of_origin",0],<br> PARAMETER["central_meridian",-75],<br> PARAMETER["scale_factor",0.9996],<br> PARAMETER["false_easting",500000],<br> PARAMETER["false_northing",0],<br> UNIT["metre",1,<br> AUTHORITY["EPSG","9001"]],<br> AUTHORITY["EPSG","26918"]]<br><br>You can also pass the entire WKT string on the commandline but that tends to<br>be difficult to quote and to remove the newlines.<br><br>Best regards,<br>-- <br>---------------------------------------+--------------------------------------<br>I set the clouds in motion - turn up | Frank Warmerdam, <a href="mailto:warmerdam@pobox.com">warmerdam@pobox.com</a><br>light and sound - activate the windows | <a href="http://pobox.com/~warmerdam">http://pobox.com/~warmerdam</a><br>and watch the world go round - Rush | Geospatial Programmer for Rent<font class="Apple-style-span" color="#000000"><font class="Apple-style-span" color="#144FAE"><br></font></font></div></blockquote></div></body></html>