In message <(E-Mail Removed). com>, Mike
Lane <(E-Mail Removed)> writes
>On Sat, 14 Feb 2009 16:32:44 +0000, Leigher wrote
>(in article <8cNy+(E-Mail Removed)>):
>
>> In message <UBell.34289$(E-Mail Removed)2>, Jolly Polly
>> <(E-Mail Removed)> writes
>>> Leigher wrote:
>>>> Hi ... would welcome some help/recommendations from the group.
>>>>
>>>> I do not own nor have ever used Sat Nav/GPS or anything similar. Usually
>>>> use OS Landranger or Explorer maps.
>>>
>>> You don't say what you want the satnav for, i.e. driving on/off road,
>>> walking, all the above, etc.
>>
>> Sorry, it would be mainly for driving on road but there will be some
>> good walking too (I hope) however am not unhappy at using maps for the
>> latter. Just don't want to waste time getting lost and missing sights
>> due to one or other being buried in a map book. Also to preserve marital
>> harmony, if possible:-))
>>
>The requirements for a gps unit used to navigate in a car are very different
>from what is needed when walking, and in my view it's a mistake to try to
>choose one unit for both purposes.
>
>Considering automobile units, it's worth remembering that there is really
>only one thing that a gps receiver can be guaranteed to do accurately, and
>that is to measure and indicate its current position. Everything else is an
>'add-on' put in by the gps manufacturers to make the unit suitable for
>different purposes, and that's where the difficulties start. I've personally
>only ever used Garmin, but whatever unit you choose for in-car use there are
>three main additional requirements:
>
>1 - accurate digital street maps. These need to contain much more than the
>physical layout of the streets - they also need to know about one-way
>systems, dual carriageways, restricted turns, etc., etc. There are two main
>companies that supply the various gps manufactures: Navteq and Tele Atlas.
>Garmin use Navteq, and Tomtom use Tele Atlas. None of the maps can be
>expected to be 100% accurate everywhere, but I would way that in western
>Europe they are extremely good, and excellent in the UK (I suspect that they
>use Ordnance Survey data for the UK mapping). The further east and south you
>go in Europe, the less reliable the maps seem to be. The Garmin website has a
>map viewer where you can look at the maps for whatever area you are
>interested in. They don't seem to list any current ones for New Zealand
>though so you might need to enquire directly from the manufacturers about
>that.
>
>2 - The unit needs software to calculate a reasonably efficient route between
>two points on the digital map. Here it depends very much on what you want.
>Most people just want to get from A to B - i.e. from their current position
>to an address, street, airport, or whatever. Most units - all the Garmin
>'Nuvi' range, for example, will do a reasonable job here. They will often not
>calculate exactly the same route you would choose yourself (but if you know
>enough to see that you don't really need the gps anyway). Most units will
>allow you to alter the route to some extent; all Nuvis for example will let
>you choose 'fastest' or 'shortest' routes. If you want more than that though
>you have to go up in the range (and pay more of course). As an example
>suppose you want to go from Southampton to Manchester, but you don't want to
>go on motorways, and you also want to avoid Birmingham, but you do want to
>pass through Stratford on Avon. With a bit of fiddling you can do all this
>(and more) with the Nuvi 5xx, 7xx and 8xx series of units and also save your
>route on the unit for future use. You do it first by setting up 'avoidances',
>which can be individual roads or entire areas that you *don't* want to pass
>through. You can then add 'Via points' which are points that you *do* want
>your route to pass through. By doing enough of this you can get the exact
>route you want and then as I said, save it for future use. Most people
>though, don't bother with this - they just want to get to some specified
>place and don't care much what route they go by.
>
>3 - The unit needs to give real time guidance as you drive. This is done by
>voice directions and the screen display. People often complain about the
>directions but I've found the Garmin units quite adequate here. You have to
>get used to your particular unit and use common sense as well. I know for
>example that mine will often direct me to turn left or right when in fact
>it's just a matter of following the road as it bends one way or the other.
>
Many thanks Mike - a lot for me to absorb. Your direction and help very
much appreciated.
Tom
--
Leigh
Deepest Dorset
|
Similar Threads
Linear Mode
