[Proj] Datum shifts in PROJ's EPSG table (The Netherlands and
	Belgium)
    Jan Hartmann 
    j.l.h.hartmann at uva.nl
       
    Fri Oct 27 05:24:40 EDT 2006
    
    
  
Hi Oscar,
The Datum shifts were derived from the EPSG database, version 6.11, nr 
55; rotations are converted from radians to arc-seconds and 
sign-reversed. This transformation supersedes nr 53, which is the one 
you use and the one mentioned in the publications on the RDNAP website. 
  The EPSG database mentions as source for 55: "Nederlandse Commissie 
voor Geodesie (NCG)". This seems to be:
A. de Bruijne, J. van Buren, A. Kösters and H. van der Marel, "De 
geodetische referentiestelsels van Nederland; Definitie en vastlegging 
van ETRS89, RD en NAP en hun onderlinge relatie". Delft: Nederlandse 
Commissie voor Geodesie (NCG), to be published in 2005
Regards,
Jan
Oscar van Vlijmen wrote:
 > Thanks for mentioning this. I still used the post-2000, but pre-2004
 > parameters which are no longer valid since 2006-01-01.
 > 
<https://rdinfo.kadaster.nl/?inhoud=/rd/nieuws-bericht.asp%3FId%3D6%26Id_Cat
egorie%3D1&navig=/rd/nav_serverside.html%3Fscript%3D1>
 >
 > The EPSG database itself has the Dutch RD 2004 transformation
 > parameters under coordinate operation 15739. For some reason they were
 > not converted to the PROJ epsg file, but Frank just mentioned epsg
 > number 4289. Here the translation figures are rounded to 3 decimals.
 > I did a bit of web searching and it appears to me that the Dutch
 > Kadaster doesn't want the new transformation procedures and parameters
 > from RDNAPTRANS 2004 to be published. You can download a file
 > rdnaptrans.zip with code, grid data, tests and explanations from the
 > download page at <http://www.rdnap.nl/> but you'll have to ask for a
 > password to deflate the zip file. The Transformator from the Kadaster
 > still uses the old stuff.
 > <https://RDinfo.kadaster.nl/rd/transformator.html>
 > All non-protected information pages still describe the old procedures
 > & parameters; for instance:
 > "Coördinaattransformaties en kaartprojecties", Ministerie van Verkeer
 > en Waterstaat, Meetkundige Dienst
 > <http://www.rdnap.nl/download/coor-en-proj.zip>
 > Apparently this reservedness serves some purpose.
 > I suppose the "confirmed" transformation:
 > <quote>
 > a more accurate definition for the Dutch system is:
 > +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,-1.87
 > 03473836068,4.0812
 > +no_defs +to +proj=latlong +datum=WGS84
 > </quote>
 > mentioned on:
 > 
<http://postgis.refractions.net/pipermail/postgis-users/2005-November/009894
.html>
 > is derived from the RDNAPTRANS 2004 procedures.
    
    
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