[Proj] Amersfoort / RD New

[Bas Couwenberg]

On 2016-11-01 12:33, Roger Oberholtzer wrote:
> I am trying to get the Amersfoort / RD New projection working with
> proj4. The users (a road authority in the Netherlands) claim to use
> this definition with ESRI:
> 
> PROJCS["RD_New",GEOGCS["GCS_Amersfoort",DATUM["D_Amersfoort",
> SPHEROID["Bessel_1841",6377397.155,299.1528128]],
> PRIMEM["Greenwich",0.0],
> UNIT["Degree",0.0174532925199433]],
> PROJECTION["Double_Stereographic"],
> PARAMETER["False_Easting",155000.0],
> PARAMETER["False_Northing",463000.0],
> PARAMETER["Central_Meridian",5.38763888888889],
> PARAMETER["Scale_Factor",0.9999079],
> PARAMETER["Latitude_Of_Origin",52.15616055555555],UNIT["Meter",1.0]]
> 
> I have started with the definition at
> http://spatialreference.org/ref/epsg/amersfoort-rd-new/proj4/. The
> projections from that are 100 meters from where they should be. I have
> seen claims that the Spatial Reference definition is incorrect, and
> that a better one is (it adds the +towgs84):
> 
> “+proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889
> +k=0.9999079 +x_0=155000 +y_0=463000 +ellps=bessel
> +towgs84=565.4174,50.3319,465.5542,-0.398957388243134,0.343987817378283,-1.87740163998045,4.0725
> +units=m +no_defs”
> 
> Still no joy. My source values are WGS84 lat/long from a GPS receiver.
> 
> Anyone have the correct proj4 definition for this?

The +towgs84 parameters as published by the Dutch Kadaster are:

  +towgs84=565.4171,50.3319,465.5524,-0.398957,0.343988,-1.877402,4.0725

These are used in the epsg file from PROJ.4 4.9.3, see:

  https://github.com/osgeonl/rdprojectie/blob/master/doc/ntv2grid.md

Alternatively you can use the RDNAP grid shift files also published by 
Kadaster. If you're on Debian/Ubuntu you can install the proj-rdnap 
package (available in jessie-backports/non-free and Ubuntu wily and 
later), otherwise you can find the download link in the PROJ.4 
documentation at:

  http://proj4.org/grids.html#netherlands
  http://www.kadaster.nl/transformatie-van-coordinaten

Use the link in the "Benadering transformatieprocedure" section to go to 
the request package and fill in the form. You'll be sent a download link 
by email.

We've recently had a mini-seminar about the correct usage of RD in open 
source software, and started collecting reference information resulting 
from that in a git repository:

  https://github.com/osgeonl/rdprojectie

You'll find more information in the linked posts on the Dutch 
mailinglist.

Kind Regards,

Bas