<div dir="ltr"><div>Hello<br><br></div>There are a few possible reasons for the differences you find. In the Oracle definition:<br><div><div><div class="gmail_extra"><br>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]]
<br><br></div><div class="gmail_extra">you have the central point (5.387639 E, 52.156161 N) rounded with 6 decimal places. The sixth decimal place is 11 cm in latitude, so it may justify differences of that order. The ellipsoid definition is correct, so it is no reason for differences.<br>
The projection you are using in PROJ.4 is "Oblique Stereographic Alternative" (+proj=sterea). PROJECTION
["Stereographic"] probably corresponds to +proj=stere, which is different.<br><br></div><div class="gmail_extra">Another possible reason are the datum transformation parameters. Check if the parameters used by Mapinfo and Oracle in the Bursa-Wolf transformation are the same you are using with cs2cs. Different sets of parameters justify differences of a few meters.<br>
<br></div><div class="gmail_extra">Regards<br><br></div><div class="gmail_extra">José Gonçalves<br></div><br><div class="gmail_extra"><br></div><div class="gmail_extra"><br><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:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div link="blue" vlink="purple" lang="EN-US">
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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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