[Proj] Belge 1972 / Belgian Lambert 72 (31370) -towgs84parameters

[Jan Hartmann]

Hi Roger,

For RD I use: +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

Yours is a older, slightly different version from the EPSG database. In 
practice, it doesn't make much difference, both are accurate up to about 
25 cm.

For a converter between Dutch and a number of neighboring projections, see:

http://www.hydro.nl/pgs/en/pctrans_en.htm/


On 28-1-2010 14:21, Roger Oberholtzer wrote:
> OOC, how do you configure proj for RD? I am using this (WGS84 Lat/Long
> is the source) in the C-API:
>
>   "+proj=sterea "
>   "+lat_0=52.15616055555555 "
>   "+lon_0=5.38763888888889 "
>   "+k=0.9999079 "
>   "+x_0=155000 "
>   "+y_0=463000 "
>   "+ellps=bessel "
>   "+towgs84=565.040,49.910,465.840,-0.40939,0.35971,-1.86849,4.0772"
>   "+units=m "
>   "+no_defs"
>
> I just want to verify that nothing has gone wrong in my library. Bit rot
> and all that.
>
> Is there a good (official?) set of test data for RD? Something that has
> WGS84 lat/longs, and the corresponding RD northings/eastings.  I can
> never have too many tests!
>
>
>