<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi there,<div><br></div><div>First off, wow, gdal is great.</div><div><br></div><div>I'm obviously new to gdal so I'm hoping that you'll put up with what I'm sure will be regarded as a "newbie" style of question.</div><div><br></div><div>I have an image from Terraserver that is in a UTM 30 projection. I need to convert it to a Equidistant Cylindrical Projection. I would like to verify that I'm using the gdalwarp command properly so I'm helping that you can help me.</div><div><br></div><div>Here's the image info I have;</div><div><br></div><div><blockquote type="cite" class=""><div><font class="Apple-style-span" color="#000000">Image Information: </font></div><div><font class="Apple-style-span" color="#000000">Date Taken: 1/1/1999</font></div><div><font class="Apple-style-span" color="#000000">Native Resolution: 15</font></div><div><font class="Apple-style-span" color="#000000">File Size: 3000 x 3000 (9.0 megapixels)</font></div><div><font class="Apple-style-span" color="#000000">Image Area: 18,225.00 sq km</font></div><div><font class="Apple-style-span" color="#000000"><br></font></div><div><font class="Apple-style-span" color="#000000">Coordinate Information: </font></div><div><font class="Apple-style-span" color="#000000">Center point Latitude: 51.46660 (51∞ 27' 60")</font></div><div><font class="Apple-style-span" color="#000000">Center point Longitude: -0.44990 (0∞ 26' 60")</font></div><div><font class="Apple-style-span" color="#000000"><br></font></div><div><font class="Apple-style-span" color="#000000">Upper left corner Latitude: 52.09038 (52∞ 5' 25")</font></div><div><font class="Apple-style-span" color="#000000">Upper left corner Longitude: -1.39985 (-1∞ 23' 59")</font></div><div><font class="Apple-style-span" color="#000000">Lower right corner Latitude: 50.83562 (50∞ 50' 8")</font></div><div><font class="Apple-style-span" color="#000000">Lower right corner Longitude: 0.47438 (0∞ 28' 28")</font></div><div><font class="Apple-style-span" color="#000000"><br></font></div><div><font class="Apple-style-span" color="#000000">Geo-reference Information: </font></div><div><font class="Apple-style-span" color="#000000">Projection: UTM Zone 30</font></div><div><font class="Apple-style-span" color="#000000">Datum: WGS 84</font></div><div><font class="Apple-style-span" color="#000000">Image Units: Meters</font></div></blockquote><br></div><div>Furthermore, here's the associated tfw file contents:</div><div><br></div><div><blockquote type="cite" class=""><div><font class="Apple-style-span" color="#000000">45.000000</font></div><div><font class="Apple-style-span" color="#000000">0.000000</font></div><div><font class="Apple-style-span" color="#000000">0.000000</font></div><div><font class="Apple-style-span" color="#000000">-45.000000</font></div><div><font class="Apple-style-span" color="#000000">609626.000120</font></div><div><font class="Apple-style-span" color="#000000">5772299.000249</font></div></blockquote></div><div><br></div><div>FInally here's the command I think I should be using:</div><div><br></div><div><blockquote type="cite" class=""><font class="Apple-style-span" color="#000000">gdalwarp -s_srs '+proj=utm +zone=30 +datum=WGS84 +x_0=609626.000120 +y_0=5772299.000249' -t_srs '+proj=eqc' -dstalpha -multi 169460-65786.tif out.tif</font></blockquote><br></div><div>I certainly get a resultant image but I'm not experienced enough with cartography to understand whether the image is correct.</div><div><br></div><div>One thing that does confuse me slightly is that the centre lat/long in the resultant image is not the same as in the source image... I would have expected that they would be, or at least that the top left corner (which is what I thinking the northerly and easterly parameters point to) should be the same.</div><div><br></div><div>Another thing: I would expect to specify either a scale, a resolution or the other corner of the image... do I need to include something more in the command for this?</div><div><br></div><div>Thanks for any enlightenment. I'm fascinated by cartography and relish the prospect of learning gdal more.</div><div><br></div><div>Kind regards,</div><div>Christopher</div></body></html>