On 26/5/05 14:03, in article
[email protected], "Rudi
Winter" <
[email protected]> wrote:
> Go on then! I'm sure many of us would be interested, and France is always
> worth a trip for some good walking.
The IGN maps (1:25) are now marked 'Compatible GPS', but it takes a while to
work out what this means!
The maps do have a grid, but the grid numbers are not printed actually on
the map as they are with OS. The co-ordinates are only on the edge of the
maps, which means that you have to have the fully open in order to do
anything with them - which is a bit of a pain.
Study the edges a bit more and you will see two sets of co-ordinates. Some
blue co-ordinates line up with a normal blue grid. A black set of
coordinates lines up with a series of occasional black lines which run true
to the terrain and are not square across the map! Now this is the good bit.
It is the black co-ordinates that you need! These, mostly, do not relate to
a line and so you have to make approximations working on their relation to
the blue grid! (Following this?).
Reading a reference off the map you will end-up with something like this:
3072 471
Now your GPS will only give you two sets of 3 co-ords. It is the 3 at the
beginning of the first set that is important.
The French grid is broken down into 4 sectors. The High Pyrenees are in Grid
Sector 3. But you try finding this out on the map itself.
The significance of this is this:
When you re-set your GPS to French co-ordinates it asks you what zone you
are in, 1-4. This is very confusing if you are doing this without knowing
how the maps work. Enter 3 and you up and running. Except ...
.... Take your GPS reading. It will be something like 072 471 for our
co-ordinates. But looking down the left hand side of the map your
co-ordinate will read 3072. The three is - of course - the sector. But
this is only listed on one set of co-ordinates!
My GPS (Magallen) tends to give a grid as III 072 471.
Now this is not that intuitive and it takes a while to get used to. This is
what you should do.
When you arrive find a place on the map where you know where you are - camp
site, etc. Work out the grid reference according to the map. And then take
a spot reading from the GPS and compare the two.
Easy. Well remember that there is a second set of co-ords that are in blue,
and with a blue grid, there is a temptation to think that these are the ones
you want.
Play around with this until you can remember what you are doing!
Happily, you rarely need a GPS on the High Route. I bought mine because I
got lost on the GR10 the year before. People assure me that this is
impossible, but I managed it! (got lost in the French equivalent of a
bloody forestry commission plantation!).
There. Finished !!!
--
Andy Howell
Birmingham, UK
To mail simply put back the dots ...
