Re: GPS Vs COMPASS

The message <bifhe15bgqsudajbcp23ods13vp8o47n9g@xxxxxxx>
from Norman <nospam@xxxxxxxxxxx> contains these words:

> >> I would think that in another 10 years no-one will be using the
> >> magnetic compass and it will go the same way as the slide rule and
> >> logarithms when the pocket calculator became available.

> >Think again. If I am still walking in 10 years time I will still be
> >using my compass to orient my map and to take bearings when it is not
> >immediately obvious from the lie of the land which way to go. Why?
> >Because I find it much simpler and much more flexible than faffing
> >around with routes and waypoints for every possible eventuality. A GPS
> >(I am on my second) is a wonderful instrument for showing where you have
> >been and, in extremis, where you are, but they are a waste of effort for
> >fair weather navigation and only of marginally greater assistance in the
> >clag.

> Clearly you must be using your GPS merely as an emergency device which
> is a shame considering the cost and benefits it has to offer.

Wrong again. I carry a GPS to tell me where I have been. I have
sufficient confidence in my own ability not to (usually) need the
comfort of absolute assurance of where I currently am.

Having once been a production engineer I am always on the lookout for
the easiest and simplest solution to any problem. As far as hill walking
navigation in clear weather is concerned map and compass wins on both
counts. It also wins on flexibility which is an issue with those who
don't stick to a rigidly planned itinerary.

> There is generally no need to bother with routes unless you want to
> keep to a clearly defined path which in the UK is nearly always
> visually discernable anyway.

Which begs the question about the nature of a "clearly defined path"
which is not "visually discernable".

> My technique with a GPS is to mark the position of my intended
> destination waypoint by saving the coordinates or transferring the
> position via my PC. Then do the same for the start point, eg car in
> car park at starting point at the beginning of a trek by pressing the
> appropriate buttons. This can be done quickly either at home or when
> you arrive at the start.

And if you happen to have chosen a route that does not lead almost
directly to your target how does go-to really help you to navigate
there?

> Normally, with a map, if you are walking up a hill etc it is usual to
> start at the bottom and gradually follow the path to the summit
> checking your route is correct by consulting your map in combination
> with compass triangulation fixes with a compass and noting/comparing
> localised terrain features with what you see around you and what is
> printed on your map. Most of the time there is no need to even look at
> a map because in clear visibility the route would be obvious by the
> errosion caused by thousands of boots churning up the ground or
> polishing the rock surfaces.

I can't even remember the last time I tried to fix my position by
triangulation. It presupposes that you don't have much of a clue where
you actually are but can still recognise 2 prominent features as unique
points. OTOH a majority of my walking (stretching back more than 40
years) seems to have been on paths that either weren't visible on the
ground or didn't exist in the first place.

> My method is to make use of all three ie map, compass and GPS
> Using a GPS switch on and select find/goto the destination waypoint
> and set off walking towards the destination by walking in the
> direction the compass rose pointer indicates. If you want to use a
> magnetic compass with the GPS you can set the GPS to give magnetic
> variation compensated bearings and every now and then switch on your
> GPS note the indicated bearing to destination and then transfer this
> to your compass and use that bearing to steer with. Using this method
> you can wander around exploring as you go. If you want to get back on
> a path, find your position using the GPS, note coordinates, look at
> map and locate present position and then work out bearing to nearest
> point on path either by compass or entering coordinates of path
> waypoint and getting the bearing to this new path waypoint from GPS
> reading. Once on path put everything back in rucksack and plod up to
> the top.

Still unnecessary faffing about. As long as you know approximately where
you are and can read a map (not always a given for some walkers) it is
easy enough to find the nearest path should you need one to get you to
your next target and just as easy to find a more direct route on the
map. Using a go-to without consulting the map is the short sighted
option. Not because you might walk off a cliff while blindly following
your GPS, not even the stupidest of individuals are likely to do that
(although it is worth bearing in mind that a German driver drove down a
slipway into a river because he failed to realise that the road he was
being guided along was interrupted by a ferry) but because the direct
route could so easily lead down a spur, not along the ridge to the next
summit.

> At top use car or start position as new destination and just do same
> procedure as previous or follow path down hill.

If you can see where you are going you don't need the assistance of a
GPS and with your crude usage it is difficult to see what advantage you
actually gain other than confirmation that you are there when you
eventually reach your target after following a path that is unlikely to
be anywhere near the straight line that your GPS is indicating.

> Interestingly all ordnance survey maps are now corrected using GPS
> derived coordinates. The triangulation points on hill tops serve as a
> nostalgic reminder of the effort that went into producing the maps.

Some of the trig points have been retained unlike the Prime Meridian
that has been hijacked by the Yanks and is now fixed to some point in
North America rather than at Greenwich Observatory. I wonder what the OS
will do as the Greenwich Meridian gradually heads West.

> I look forward to the day when one can buy a device that you can put
> in your pocket and when you want to know where you are you can just
> ask it to tell you or show you on a 1 in 25000 colour map.

Even then it will still be just as easy to use a map and compass
provided the map is of a manageable size. Maybe even easier given
current screen sizes.

--
Roger Chapman so far this year 50 summits
New - 27 (Marilyns 13, Nuttalls 5, Outlying Fells 10)
Repeats - 23 (Marilyns 7, Nuttalls 14, Wainwrights 12, Outlying Fells 0)
.