# Defining a local CRS that is basically UTM31N rotated by 43.22 degrees

Working with some data in the North Sea and basically I'm a bit fed up of working at a slant of 43.22 degrees. I was thinking it must be possible to define an orthogonal local coordinate system as a .prj file for my area. However I have no idea how to do this...

The desired centre of such a grid would be at 2°0'0"E 55°0'0"N and rotated by -43.22 or +46.78 so that the boxes in the image below go from rotated to orthogonal.

I managed to solve this myself by defining a .prj using a tutorial found at:

For anyone to check, I used the bottom left corner as my origin and set the rotation to -43.22/136.78 and ended up with:

PROJECTION["Local"], PARAMETER["False_Easting",0.0], PARAMETER["False_Northing",0.0], PARAMETER["Scale_Factor",1.0], PARAMETER["Azimuth",-43.22], PARAMETER["Longitude_Of_Center",1.42624], PARAMETER["Latitude_Of_Center",55.102476],UNIT["Meter",1.0]]

– PolyGeo
Jun 7, 2016 at 21:51

Alternatively to your solution (which seems to work in ARCGIS), you can set up an oblique mercaor projection. This would work in QGIS and GDAL-based software as well:

PROJ.4 :

``````+proj=omerc +lat_0=55.102476 +lonc=1.42624 +alpha=-43.22 +k=0 +x_0=0 +y_0=0 +gamma=0 +datum=WGS84 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
``````

OGC WKT :

``````PROJCS["unnamed",
GEOGCS["WGS 84",
DATUM["WGS_1984",
SPHEROID["WGS 84",6378137,298.257223563,
AUTHORITY["EPSG","7030"]],
TOWGS84[0,0,0,0,0,0,0],
AUTHORITY["EPSG","6326"]],
PRIMEM["Greenwich",0,
AUTHORITY["EPSG","8901"]],
UNIT["degree",0.0174532925199433,
AUTHORITY["EPSG","9122"]],
AUTHORITY["EPSG","4326"]],
PROJECTION["Hotine_Oblique_Mercator_Azimuth_Center"],
PARAMETER["latitude_of_center",55.102476],
PARAMETER["longitude_of_center",1.42624],
PARAMETER["azimuth",-43.22],
PARAMETER["rectified_grid_angle",0],
PARAMETER["scale_factor",0],
PARAMETER["false_easting",0],
PARAMETER["false_northing",0],
UNIT["Meter",1]]
``````