[Proj] proj and Dutch RD

[Roger Oberholtzer]

xOn Wed, 2006-01-11 at 17:14 +0200, Martin Vermeer wrote: 
> On Wed, 2006-01-11 at 15:31 +0100, Roger Oberholtzer wrote:
> > I am trying to use proj on a Dutch project using 'RD'. I have
> > encountered a problem.
> > 
> > I am trying the command:
> > 
> > 	cs2cs -r +proj=latlong +ellps=WGS84 +to +proj=stere
> > +lat_0=52.15616055555555 +lon_0=5.38763888888889 +k=0.9999079
> > +x_0=155000 +y_0=463000 +ellps=bessel +units=m +no_defs
> > 
> > This is based on the definition is the 'esri' file for item 28922.
> > 
> > The X/Y values I get are not correct (according to our contact). I have
> > attached a small set of values, which contains:
> > 
> > 	latitude and longitude in degrees (WGS84)
> > 
> > 	easting and northing according to our contact
> > 
> > 	easting, northing and altitude from cs2cs with command line shown above
> > 
> > I have stuck to cs2cs for this to eliminate any programming error on my
> > part (other than the command line).
> > 
> > I have a configuration file for this from my contact. It looks like
> > this, which is pretty much what I wave on the command line. 
> > 
> > 	PROJCS["Rijksdriehoekstelsel_New",
> > 	GEOGCS["GCS_Amersfoort",
> > 	DATUM["D_Amersfoort",
> > 	SPHEROID["Bessel_1841",6377397.155,299.1528128]],
> > 	PRIMEM["Greenwich",0],
> > 	UNIT["Degree",0.0174532925199432955]],
> > 	PROJECTION["Double_Stereographic"],
> > 	PARAMETER["Scale_Factor",0.9999079],
> > 	PARAMETER["False_Easting",155000],
> > 	PARAMETER["False_Northing",463000],
> > 	PARAMETER["Central_Meridian",5.38763888888889],
> > 	PARAMETER["Latitude_Of_Origin",52.15616055555555],
> > 	UNIT["Meter",1]]
> > 
> > The 'PARAMETER' items match my command line. I am not sure about the
> > others, like the DEGREE unit and the Bessel values.
> 
> Try
> 
> cs2cs -r +proj=latlong +ellps=bessel +to +proj=stere
> +lat_0=52.15616055555555 +lon_0=5.38763888888889 +k=0.9999079
> +x_0=155000 +y_0=463000 +ellps=bessel +units=m +no_defs
> 
> I assume that your given lat, long coordinates are already on Bessel ;-)

They are WGS84 values from a Trimble GPS. Now I am confused. When doing
a KKJ conversion (Finland), I had to specify the source lat/long as
+ellps=wgs84. But your spec pus the values within 0.3 meters of the
target. Hum...


-- 
Roger Oberholtzer
OPQ Systems AB