OpenStreetMap
While examining the limits of the internal zones in UK waters, a recent Statutory Instrument defines one of the points on a boundary as being at longitude 02°42'95"W. Anyone know what I'm supposed to make of this? Other than the usual government incompetence, of course.
Discussion
Comment from RichardB on 17 August 2010 at 22:43
I've seen the document for the Welsh border - and it has many points with greater than 60" - too many for it to be an isolated mistake. Perhaps they're not seconds of arc, but decimal minutes? In which case, your coord is 51º32.53' N, 2º42.95' W
Comment from RichardB on 17 August 2010 at 23:37
Right, they are in decimal minutes, and not seconds of arc. The reason I can tell is because most of the coordinates are also defined in SI 1999/762 - which defines the border in the Dee & Severn Estuaries. If you convert the coords in SI1999/762 from OSBG36->WGS84 - then the points lie extremely close to those from the latest document with decimal minutes - but much further away with seconds of arc.
Comment from chriscf on 18 August 2010 at 00:35
I have worked on that assumption for the Welsh points, and not on that assumption for the Scottish baseline (the points fit better as arcseconds than decimal minutes). However, I realize I may have accidentally used the decimal minute conversion for the Northern Ireland limits, so will probably need to reimport those (and redraw the lines).