<div dir="ltr"><div><div><div><div><div><div><div><div>Hello Jelmer,<br><br></div></div></div>1. I would strongly advice to transform everything to wgs84 first.<br></div>2. wgs84 and etrs89 are based upon different spheroids/datums. Transforming from wgs84 TO etrs89 will not be correct if your etrs89 definition does not have +towgs84 defined. And by default I believe it isn't. Take a look at this ticket: <a href="http://trac.osgeo.org/proj/ticket/15">http://trac.osgeo.org/proj/ticket/15</a> and see if it is of any help.<br>
</div><br></div>So, what I would do is:<br><br></div>epsg:28992 -> wgs84 (visual check) -> etrs89<br><br></div>Good luck!<br><div><div><div><div><div><div><div><div><br><br></div></div></div></div></div></div></div>
</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">2013/7/30 Jelmer Baas <span dir="ltr"><<a href="mailto:baas@speerit.nl" target="_blank">baas@speerit.nl</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<p><span lang="NL">Hello,<u></u><u></u></span></p>
<p><span lang="NL"><u></u> <u></u></span></p>
<p>For a new project we need to convert coordinates from EPSG 28992 to EPSG 3044 with MapInfo, Oracle AND a few Proj.4 programs (PostGIS, a custom DLL, Proj4js). The problem we are having is that we're seeing some shifted coordinates.<u></u><u></u></p>
<p><u></u> <u></u></p>
<p>First test point (in the Netherlands)<u></u><u></u></p>
<p><span style="font-family:"Courier New"">Origin 135745.924 517131.216<u></u><u></u></span></p>
<p><span style="font-family:"Courier New"">Proj4js 236345.39474983042 5839505.550959114<u></u><u></u></span></p>
<p><span style="font-family:"Courier New"">Postgis(1) 236345.390264227 5839505.55017783<u></u><u></u></span></p>
<p><span style="font-family:"Courier New"">Postgis(2) 236345.394817119 5839505.55055913<u></u><u></u></span></p>
<p><span style="font-family:"Courier New"" lang="NL">MapInfo 236345.47 5839504.058<u></u><u></u></span></p>
<p><span style="font-family:"Courier New"" lang="NL">CS2CSN 236345.39 5839505.55<u></u><u></u></span></p>
<p><span style="font-family:"Courier New"">DLL old(4) 236345.396465174 5839505.54496813<u></u><u></u></span></p>
<p><span style="font-family:"Courier New"">DLL new(3) 236345.390259674 5839505.55009311<u></u><u></u></span></p>
<p><span style="font-family:"Courier New"">Oracle 236345.49107424 5839504.12246656<u></u><u></u></span></p>
<p><u></u> <u></u></p>
<p>Test point (in Germany)<u></u><u></u></p>
<p><span style="font-family:"Courier New"">Origin 254870.45 415123.56<u></u><u></u></span></p>
<p><span style="font-family:"Courier New"">MapInfo 350265.960 5731670.259<u></u><u></u></span></p>
<p><span style="font-family:"Courier New"">Postgis(1) 350263.4072329 5731667.880
<u></u><u></u></span></p>
<p><span style="font-family:"Courier New"">Postgis(2) 350263.4132521 5731667.880
<u></u><u></u></span></p>
<p><span style="font-family:"Courier New"">DLL new(3) 350263.407243136 5731667.88019826
<u></u><u></u></span></p>
<p><span style="font-family:"Courier New"">DLL old(4) 350263.403514925 5731667.88565864
<u></u><u></u></span></p>
<p><span style="font-family:"Courier New"">Oracle(5) 350265.967728329 5731670.33312477
<u></u><u></u></span></p>
<p><span style="font-family:"Courier New"">CS2CS 350263.41 5731667.88 43.92 cs2cs +init=EPSG:28992 +to +init=EPSG:3044<u></u><u></u></span></p>
<p><u></u> <u></u></p>
<p>It seems MapInfo and Oracle more-or-less agree, as do all Proj.4-based products. I don’t know which are “right”, meaning I also don’t know which ones are wrong – let alone find the fault.
<u></u><u></u></p>
<p><u></u> <u></u></p>
<p>Hopefully someone can help me with this problem, or at least point me in the right direction.<u></u><u></u></p>
<p><u></u> <u></u></p>
<p>(1): <span style="font-family:"Courier New"">"+proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889 +k=0.9999079 +x_0=155000 +y_0=463000 +ellps=bessel +towgs84=565.417,50.3319,465.552,-0.398957,0.343988,-1.8774,4.0725 +units=m
+no_defs "<u></u><u></u></span></p>
<p>(2) Another server where I updated the spatial_ref_system:
<span style="font-family:"Courier New"">"+proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889 +k=0.9999079 +x_0=155000 +y_0=463000 +ellps=bessel +units=m +towgs84=565.2369,50.0087,465.658,-0.406857330322398,0.350732676542563,-1.8703473836068,4.0812
+no_defs no_defs"<u></u><u></u></span></p>
<p>(3) A custom built DLL for usage in VB6. "+proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889 +k=0.999908 +x_0=155000 +y_0=463000 +ellps=bessel +units=m +towgs84=565.2369,50.0087,465.658,-0.406857330322398,0.350732676542563,-1.8703473836068,4.0812
+no_defs <>"<u></u><u></u></p>
<p>(4) Same DLL. “+proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889 +k=0.9999079 +x_0=155000 +y_0=463000 +ellps=bessel +towgs84=565.417,50.3319,465.552,-0.398957,0.343988,-1.8774,4.0725 +units=m +no_defs <>”<u></u><u></u></p>
<p>(5)<span style="font-family:"Courier New""> select sdo_cs.transform(SDO_GEOMETRY('POINT(254870.45 415123.56)', 90112),25832) from dual;<u></u><u></u></span></p>
<p>(5b) The Oracle definition contains some tags I don’t see anywhere in Proj.4 (like the Bessel 1841 part): <u></u><u></u></p>
<p>PROJCS["Netherlands National System", GEOGCS [ "Netherlands Bessel", DATUM ["Netherlands Bessel", SPHEROID ["Bessel 1841", 6377397.155, 299.1528128]], PRIMEM [ "Greenwich", 0.000000 ], UNIT ["Decimal Degree", 0.01745329251994330]], PROJECTION
["Stereographic"], PARAMETER ["Scale_Factor", 0.999908], PARAMETER ["Central_Meridian", 5.387639], PARAMETER ["Latitude_Of_Origin", 52.156161], PARAMETER ["False_Easting", 155000.000000], PARAMETER ["False_Northing", 463000.000000], UNIT ["Meter", 1.000000000000]]
<u></u><u></u></p>
<p><u></u> <u></u></p>
<p>A side note is that transformation via my DLL doesn’t work properly (i.e., coordinates are shifted tens of meters), unless I *<b>first</b>* transform to WGS84 and then to 3044. I assume this is caused by an easy-to-fix error, but I don’t
know what that is.<u></u><u></u></p>
<p><u></u> <u></u></p>
<p>P.S.: PostGIS, Proj4JS and my epsg file are all up-to-date.<u></u><u></u></p>
<p><u></u> <u></u></p>
<p>Thanks for any help,<u></u><u></u></p>
<p><u></u> <u></u></p>
<p><span lang="NL">With kind regards,<u></u><u></u></span></p>
<p><span lang="NL">Jelmer Baas<u></u><u></u></span></p>
<p><span lang="NL"><u></u> <u></u></span></p>
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