[Proj] Finnish KKJ in proj 4.4.9
roger at opq.se
Tue Dec 13 03:15:55 EST 2005
On Mon, 2005-12-12 at 23:01 +0200, Martin Vermeer wrote:
> On Mon, Dec 12, 2005 at 04:18:57PM +0100, Roger Oberholtzer wrote:
> > I am exploring using proj to obtain KKJ coordinates from WGS84 lat/long
> > values. The values only get to within 176 meters of where they are
> > expected to be (according to the Finnish Road Authority). Is anyone else
> > using proj to obtain Finnish KKJ values?
> > --
> > Roger Oberholtzer
> > OPQ Systems AB
> Which are you using? I tried <2393> from the epsg file:
> # KKJ / Finland Uniform Coordinate System
> <2393> +proj=tmerc +lat_0=0 +lon_0=27 +k=1.000000 +x_0=3500000 +y_0=0
> +ellps=intl +towgs84=-90.7,-106.1,-119.2,4.09,0.218,-1.05,1.37 +units=m
> +no_defs <>
I got closest with:
# KKJ / Finland zone 2
<2392> +proj=tmerc +lat_0=0 +lon_0=24 +k=1.000000 +x_0=2500000 +y_0=0
+ellps=intl +towgs84=-90.7,-106.1,-119.2,4.09,0.218,-1.05,1.37 +units=m
That was the one that got me to within 176 meters.
> just last week, and got within decimetres of the right values according
> to the Ollikainen publication.
> The command I used was
> ./cs2cs +proj=latlong +ellps=WGS84 +to +init=epsg:2393
I have been trying via the C API. I gave that string to pj_init_plus(),
which should use those strings.
> The test point I use is triangulation point 158:
> 23d55'11.134"E 63d29'4.016"N 23.847
> 3346722.90 7046208.88
> from Matti Ollikainen (1993): GPS-koordinaattien muuntaminen
> Kartastokoordinaateiksi, pages 29-31 (Finnish Geodetic Institute)
> Are you sure you are using the right zone? There are four of them,
> 2391-2394, three degrees apart.
I tried them all. The one above gets me closest.
I have a Windows program that claims to do the correct transformations:
Program name EurefMuunnos
Author and date Sakari Haljala, NLS 4.9.2003
Copyright National Land Survey of Finland, Helsinki 2003
This is what we are trying to match. These are some sample data points
EUREF-FIN- geographic coordinates in format: aamm.mmm = degrees+minutes
KKJ- plane coordinates in Gauss-Krüger zone no. 2 (northing, easting):
How would I set that up in cs2cs? The input is EUREF-FIN, not WGS84. In
fact, my real data (not these test points) will be WGS84 from a GPS
receiver. But I would like to verify these points as well.
OPQ Systems AB
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