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<body bgcolor="#FFFFFF"><div><br>I don't know what the trouble is, but maybe GeoTIFF doesn't support Mercator with</div><div>a lat_ts parameter (latitude of true scale). If so, you can try to use a scale factor instead. </div><div><br></div><div>That is, replace your</div><div><br></div><div> +lat_ts=41.5</div><div><br></div><div>by</div><div><br></div><div> +k_0=0.750058844766239</div><div><br></div><div>This will give you an equivalent definition, and maybe it will work better. </div><div><br></div><div>Best regards,</div><div><br></div><div>Mikael Rittri</div><div>Carmenta</div><div>Sweden</div><div><a href="http://www.carmenta.com">http://www.carmenta.com</a></div><div><br>18 jul 2012 kl. 19:16 skrev "Geoff Shipton" <<a href="mailto:geoff@tritonimaginginc.com">geoff@tritonimaginginc.com</a>>:<br><br></div><div></div><blockquote type="cite"><div><div class="WordSection1"><p class="MsoNormal">Hello everyone,<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">We “inherited” this Proj4 string from a previous product – it has always seemed to work but we are having problems using it with gdalwarp, the warped .tif image looks valid but has errors in the TIF tags. If anybody has any idea what’s wrong I would be grateful. Comparing it with other Mercator Proj4 strings it looks a bit simple…<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Here’s the string:<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">+proj=merc +datum=WGS84 +lon_0=0 +lat_ts=41.5 +x_0=0 +y_0=2000000<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">I am not a geodesist, be gentle.<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Many thanks,<o:p></o:p></p><p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:12.0pt;font-family:"Times New Roman","serif"">Geoff Shipton,<br>Triton Imaging Inc.<br>Customer Support.<br>Capitola CA.<br><a href="mailto:geoff@tritonimaginginc.com"><span style="color:blue">geoff@tritonimaginginc.com</span></a><br><br></span><span style="font-size:8.0pt;font-family:"Times New Roman","serif"">The information contained in this message may be privileged or confidential information intended solely for the use of the addressee(s). Any views or opinions presented in this communication do not necessarily represent those of Triton Imaging, Inc. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please immediately notify me and you are hereby instructed to delete all electronic copies and destroy all printed copies.</span><span style="font-size:12.0pt;font-family:"Times New Roman","serif""><o:p></o:p></span></p><p class="MsoNormal"><o:p> </o:p></p></div></div></blockquote><blockquote type="cite"><div><span>_______________________________________________</span><br><span>Proj mailing list</span><br><span><a href="mailto:Proj@lists.maptools.org">Proj@lists.maptools.org</a></span><br><span><a href="http://lists.maptools.org/mailman/listinfo/proj">http://lists.maptools.org/mailman/listinfo/proj</a></span></div></blockquote></body></html>