GPS Coordinate transformations

Olly Betts
Thu, 5 Sep 2002 15:08:01 +0100

Sorry for a very belated reply (nearly 8 months later!)

On Sun, Jan 13, 2002 at 09:05:36PM +0000, J Wood wrote:
> 1. Can anyone point me in the direction of the appropriate transformation
> from GPS Lat, Lon, Height to UK OS grid reference?

GEO can do conversions between pretty much any pair of coordinate
systems.  It's a bit cryptic though - you need to write a script file
to convert coordinates:

As others suggested, you could just type coordinates into a GPS and read
them back in the other system.  However I've read that some GPS units use
simplified coversion formulae which only approximate the correct answer.
Which units and how approximate I don't know I'm afraid.

> 2. What was the software used for the CUCC presentation at Hidden Earth
> last autumn?

It was a development version of Survex, using opengl to do the 3d stuff.
The version you saw was hardwired to view the particular terrain and map
overlay used and had a number of shortcomings which I carefully avoided
highlighting in the presentation.

It showed us that a different approach was needed to get opengl working
well.  Mark has since restructured Aven in the light of the experience
and implemented opengl support much more cleanly.  I'm hoping we can get
out a stable test version of this which does 3d passages by the end of
this month so people can try it out and comment on it.

Once that's done, we can incorporate the terrain and draped maps fairly