How to parametrize .prj WKT file so that I can perform 7 point tranformation (wiki). I know how
false_easting and false_northing params work, but how can I adjust scale? I do not mean scale_factor'
That's the problem description:
I have transportation network (vector layer) saved in non-GIS environment (transport modeling software). Network consists of nodes (points) and polylines (road links). It's done mostly from random backgrounds, regardless any projection, coordinates, etc.
I need to set appropriate projection for the network.
I have accesss to .prj files (if I'm in an say WGS84 projection I can switch to any other projection)
So that's what I'm trying:
I try 7 point Helmert Transformation (http://proj.maptools.org/gen_parms.html). I use towgs84 transformation as a WKT param in .prj file, where I assume that rotation matrix is zero (can I do so?) and I calculate only delta_x, and delta_y, and scale param.
However it will not work. This is my .prj , params in TOWGS84 do not affect transformation:
PROJCS["UTM 17 (WGS84) in northern hemisphere.", GEOGCS["WGS 84", DATUM["WGS_1984", SPHEROID["WGS 84",6378137,298.257223563], TOWGS84[0,0,0,0,0,0,100000000000000000000000]], PRIMEM["Greenwich",0], UNIT["DMSH",0.0174532925199433], AXIS["Lat",NORTH], AXIS["Long",EAST], PROJECTION["Transverse_Mercator"], PARAMETER["latitude_of_origin",0], PARAMETER["central_meridian",0], PARAMETER["scale_factor",1], PARAMETER["false_easting",0], PARAMETER["false_northing",0]]
So I tried to use
false_easting params, and those work good, and transform my network proprely, BUT:
It will not chcange scale of my network, only position. So how can I rescale my network using .prj file?
Thanks for any hints