Hiya,<br><br><div class="gmail_quote">On Sat, Mar 14, 2009 at 11:28 AM, Paul Ramsey <span dir="ltr"><<a href="mailto:pramsey@opengeo.org">pramsey@opengeo.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
Since I can't verify, I'll just give you my guess:<br>
<br>
+proj=merc +lat_ts=-46 +lon_0=100 +x_0=0 +y_0=0 +ellps=clrk66<br>
<div><div></div><div class="h5"></div></div></blockquote><div><br></div><div>Some working behind Paul's "guess" (via Python+GDAL)....<br><br><blockquote class="webkit-indent-blockquote" style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 40px; border-top-style: none; border-right-style: none; border-bottom-style: none; border-left-style: none; border-width: initial; border-color: initial; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; ">
<span class="Apple-style-span" style="font-family: 'courier new'; font-size: 12px; ">from osgeo.osr import SpatialReference</span><br><span class="Apple-style-span" style="font-family: 'courier new'; font-size: 12px; ">s = SpatialReference()<br>
</span><br><span class="Apple-style-span" style="font-family: 'courier new'; font-size: 12px; ">s.ImportFromWkt('PROJCS["Clarke_1866_Mercator",GEOGCS["GCS_Clarke_1866",DATUM["D_Clarke_1866",SPHEROID["Clarke_1866",6378206.4,294.9786982]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Mercator"],PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",100.0],PARAMETER["Standard_Parallel_1",-46.0],UNIT["Meter",1.0]]')</span><br>
<span class="Apple-style-span" style="font-family: 'courier new'; font-size: 12px; ">>>> 0<br></span><br><span class="Apple-style-span" style="font-family: 'courier new'; font-size: 12px; ">s.ExportToProj4()</span><br>
<span class="Apple-style-span" style="font-family: 'courier new'; font-size: 12px; ">>>> ERROR 6: No translation for Mercator to PROJ.4 format is known.</span><br><br><span class="Apple-style-span" style="font-family: 'courier new'; font-size: 12px; ">s.ImportFromWkt('PROJCS["Clarke_1866_Mercator",GEOGCS["GCS_Clarke_1866",DATUM["D_Clarke_1866",SPHEROID["Clarke_1866",6378206.4,294.9786982]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],<span class="Apple-style-span" style="color: rgb(255, 0, 0); "><span class="Apple-style-span" style="font-weight: bold;">PROJECTION["Mercator_2SP"]</span></span>,PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",100.0],PARAMETER["Standard_Parallel_1",-46.0],UNIT["Meter",1.0]]')</span><br>
<span class="Apple-style-span" style="font-family: 'courier new'; font-size: 12px; ">>>> 0<br></span><br><span class="Apple-style-span" style="font-family: 'courier new'; font-size: 12px; ">s.ExportToProj4()</span><br>
<span class="Apple-style-span" style="font-family: 'courier new'; font-size: 12px; ">'+proj=merc +lon_0=100 +lat_ts=-46 +x_0=0 +y_0=0 +ellps=clrk66 +units=m +no_defs '</span><br></blockquote><br>Mercator 2SP seems to be what you want: you have a latitude & a longitude instead of a longitude and a scale (1SP). <a href="http://www.remotesensing.org/geotiff/proj_list/mercator_2sp.html ">http://www.remotesensing.org/geotiff/proj_list/mercator_2sp.html </a> <br>
<div><br></div><div>HTH, </div><div><br></div><div>Rob :)</div></div></div>