RE: [Geotools-gt2-users] Transformation question (CannotCreateTra nsformationException)

[Simon B. <sb...@ga...>]

Hello,

What you need is the WKT "TOWGS84" element

e.g. for the RT90 2.5 gon W coordinate system (Sweden) the WKT (including
the TOWGS84 element)

PROJCS["RT90 2.5 gon
W",GEOGCS["RT90",DATUM["Rikets_koordinatsystem_1990",SPHEROID["Bessel
1841",6377397.155,299.15281], TOWGS84[-141.1055246174, -41.3265500042,
-603.0582474221, -0.855116377, 2.1413174055, -7.0227298286, 0.0]],
PRIMEM["Greenwich",0],UNIT["degree",0.0174532925199433]],PROJECTION["Transve
rse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian
",15.8082777777778],PARAMETER["scale_factor",1],PARAMETER["false_easting",15
00000],PARAMETER["false_northing",0],UNIT["metre",1]]


Bursa wolf parameters are the   x, y, z shift & x, y, z rotate, and scale.
These are used by ct-coordtrans to convert the coordinates. If you need to
find out what the parameters are look in the epgs database, MS-Access
downloadable from http://www.epsg.org/

Regards,

Simon
-----Original Message-----
From: Johansen Per Henrik [mailto:ph...@no...]
Sent: 08 October 2003 13:44
To: geo...@li...
Subject: [Geotools-gt2-users] Transformation question
(CannotCreateTransformationException)


Hi,

I am new to using coordinate transformations with geotools (and in general).
I have a question on how to do this using ct and cs packages.

What I want to do is create a source and a target coordinate system from WKT
and then create a transformation. The WKT's are generated with
org.geotools.cs.CoordinateSystemEPSGFactory (codes 32632 and 32632). They
look like this:

ngoWKT:
PROJCS["NGO 1948 (Oslo) / NGO zone III", GEOGCS["NGO 1948 (Oslo)",
DATUM["NGO 1948 (Oslo)", SPHEROID["Bessel Modified", 6377492.018,
299.1528128, AUTHORITY["EPSG","7005"]], AUTHORITY["EPSG","6817"]],
PRIMEM["Oslo", 10.722916666666666, AUTHORITY["EPSG","8913"]], UNIT["degree
of angle",0.017453292519943295], AXIS["Geodetic latitude",NORTH],
AXIS["Geodetic longitude",EAST], AUTHORITY["EPSG","4817"]],
PROJECTION["Transverse_Mercator"], PARAMETER["semi_major", 6377492.018],
PARAMETER["semi_minor", 6356173.508712696], PARAMETER["central_meridian",
0.0], PARAMETER["latitude_of_origin", 58.00000000000001],
PARAMETER["scale_factor", 1.0], PARAMETER["false_easting", 0.0],
PARAMETER["false_northing", 0.0], UNIT["metre",1.0], AXIS["Northing",NORTH],
AXIS["Easting",EAST], AUTHORITY["EPSG","27393"]]

utmWKT:
PROJCS["WGS 84 / UTM zone 32N", GEOGCS["WGS 84", DATUM["World Geodetic
System 1984", SPHEROID["WGS 84", 6378137.0, 298.257223563,
AUTHORITY["EPSG","7030"]], AUTHORITY["EPSG","6326"]], PRIMEM["Greenwich",
0.0, AUTHORITY["EPSG","8901"]], UNIT["degree of
angle",0.017453292519943295], AXIS["Geodetic latitude",NORTH],
AXIS["Geodetic longitude",EAST], AUTHORITY["EPSG","4326"]],
PROJECTION["Transverse_Mercator"], PARAMETER["semi_major", 6378137.0],
PARAMETER["semi_minor", 6356752.314245179], PARAMETER["central_meridian",
9.0], PARAMETER["latitude_of_origin", 0.0], PARAMETER["scale_factor",
0.9996], PARAMETER["false_easting", 500000.0], PARAMETER["false_northing",
0.0], UNIT["metre",1.0], AXIS["Easting",EAST], AXIS["Northing",NORTH],
AUTHORITY["EPSG","32632"]]

My code looks like this:

		CoordinateSystemFactory csFactory =
CoordinateSystemFactory.getDefault();
		CoordinateSystem sourceCS = null;
		CoordinateSystem targetCS = null;
		try {
			sourceCS =
csFactory.createFromWKT(ngoWKT.toString());
			targetCS =
csFactory.createFromWKT(utmWKT.toString());
		} catch(FactoryException fe) {
			return null;
		}
		
		CoordinateTransformationFactory trFactory =
CoordinateTransformationFactory.getDefault();
		CoordinateTransformation transformation = null;
		try {
			transformation =
trFactory.createFromCoordinateSystems(sourceCS, targetCS);
		} catch(CannotCreateTransformException te) {
			te.printStackTrace();
			return null;
		}

When I execute the code it fails with the Exception: 
	org.geotools.ct.CannotCreateTransformException: Bursa wolf
parameters required.

Obvioulsy I am doing something wrong, and wonder what it is.

Any help is welcome.

Regards,

Per Henrik
--
Per Henrik Johansen



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