[Proj] Finnish KKJ in proj 4.4.9

[Roger Oberholtzer]

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
+no_defs  <>

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
they provided:

EUREF-FIN- geographic coordinates in format: aamm.mmm = degrees+minutes
(latitude, longitude):

6011.048456 2456.961511

6011.917399 2456.117327

6012.283731 2455.387040

6013.139141 2457.086345 

6010.570229 2455.930532 

6012.467191 2456.127325

6013.045471 2458.825683 

KKJ- plane coordinates in Gauss-Krüger zone no. 2 (northing, easting):

6675107.237 2552856.284 

6676709.563 2552052.761

6677380.277 2551368.203 

6678990.902 2552915.797 

6674205.682 2551915.400 

6677730.555 2552047.542 

6678840.480 2554525.154 

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.

-- 
Roger Oberholtzer
OPQ Systems AB