Dear all, Ordnance Survey has a database of triangulation stations and their precise locations as OSGB36 (National Grid) co-ordinates publicly available here: https://www.ordnancesurvey.co.uk/gps/legacy-control-information/triangulation-stations. There is also a FOI request with a full CSV file here: https://www.ordnancesurvey.co.uk/about/governance/foi/questions/2015/0056.html. I'm not sure under what licence the co-ordinates are published though.
It struck me that accurate co-ordinates for the visible stations such as church spires, masts and water towers could be helpful in accurately determining the offset of aerial imagery. It's possible to convert the CSV to a GPX file with WGS84 lat/lon using QGIS (although I couldn't get JOSM to display the metadata for each point). The imagery can then be aligned to these points, bearing in mind of course that the imagery is often taken from an angle (see http://wiki.openstreetmap.org/wiki/Roof_modelling#Drawing_of_simple_building_outlines). Best wishes, Greg. _______________________________________________ Talk-GB mailing list Talk-GB@openstreetmap.org https://lists.openstreetmap.org/listinfo/talk-gb
