On 09/05/11 12:00, TimSC wrote: > The OS national grid has been around for a long time and has been > adjusted and tweaked as measurement accuracy has improved. The official > transform from the national grid (OSGB36) to GPS lat lon (WGS84) is > known as OSTN02. OSTN02 uses a large look up table to account for the > strange shape of OSGB36. There are of course various mathematical > approximations of OSTN02 which are easier to use. I am not sure which > transformation Garmin uses but it seems to be accurate enough.
When was the OSTN02 table published? Only my understanding has always been that OS claim some sort of intellectual property rights over the data in that table and hence people have generally used algorithmic approximations to avoid licensing issues. Tom -- Tom Hughes (t...@compton.nu) http://compton.nu/ _______________________________________________ Talk-GB mailing list Talk-GB@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-gb
