[Gvsig_english] 2D non projected coordinates conversion to EPSG 27700?

[Antonio Gennarini]

Hi,

I have a series of locations (groundwater abstractions boreholes) from a
groundwater model in a shapefile where the locations are not
georeferenced. They are referred to a local zero (0,0) so that Borehole
1 has coordinates 345.90,450.87, Borehole 2 has coordinates 443.98,
554.87 and so on (but the coordinates are in meters).

I'm trying to figure out how to convert the above shapefile into one
that is georeferenced to EPSG 27700 (OSBG). The assumption is that the
relative distance between the boreholes is maintained constant when
moving from one system to the other. The point is that I need to
georeference my boreholes to actual coordinates rather than to model
(local) coordinates that have no geographic correspondence.
Also, while I have model coordinates for all 1000 borehole, I have model
coordinates and geographic coordinates for only 250 of the boreholes
(maybe some of these 250 could be used as control points?).

Is there a way to georeference my model shapefile, that is currently in
local coordinates, to a projected (EPSG 27700 which corresponds to
Ordnance Survey GB) coordinate system? Maybe I could use the borehole
locations that have model coordinates and OSGB? Precision and accuracy
are not an great issue here as the groundwater model is a regional model
where the cells are 250 m x 250 m.

Thanks

Antonio Gennarini
Project Consultant
-------------------------------------
ESI Ltd
Soil and Groundwater Specialists
New Zealand House
160, Abbey Foregate
Shrewsbury SY2 6FD
Telephone: +44 (0)1743 276100 Direct Dial: +44 (0)1743 276145
Fax: +44 (0)1743 248600
Email antoniogennarini at esinternational.com
<http://www.esinternational.com> 
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