"Joe Lauton" <JL.DeleteThis@Lauton2000.com> wrote in message
news:aafpl21logro5u6qub9sajek6h0i8g0nvf@4ax.com...
> Are the GPS packages really any good? The GM thing can apparently be
> miles off or slow. Same difference.
> The stand alone ones run $400-600 so at that price one may as well get
> a laptop based one - with a GPS package. What works? Did a google
> and found nothing useful.
> joe
Try asking over in newsgroup sci.geo.satellite-nav. It would be polite, of
course, to download all the headers you can and see if someone else has
already asked the question or one similar and then ask followups if it's
already been addressed.
Or try this web site:
www.gpsinformation.net
One of the first few items on that page is a link to an article about "my
first gps for automobile" and the utility of the site generally is high.
My $.02 - paper maps are the better value, unless you go so many different
places you'd need a trunk full of them.
The screens on those auto units are kind of small and I also think there'd
be an unfortunate tendency to start an "IFR driving style" (i.e.,
principally watching the screen, rather than the road), which could lead to
"adverse outcomes in automotive itinerary execution."
As for the systems themselves, in decent conditions, GPS technology, with
WAAS correction, can tell you "you are here" with impressive accuracy (to
within 10 feet - or little more than the width of your lane). At least,
they do so MOST of the time. Sometimes, not so hot. In the city, with tall
buildings and obstructed sky views, you might have accuracy and multipath
problems and your GPS could start lying to you. I have a handheld unit for
walking and biking and, one day, it was entirely wrong by about a half mile
for a portion of a 3 mile trip and my peak speed was about 1000 mph. Wow!
That's pedalling!
Then there's the quality of the map database. If the map source is wrong,
then you'll get interesting results from routing and directions. Mostly, I
guess they're pretty good, or you'd hear more about their errors. New roads
might not show up for a couple of years (I don't know) and closed roads
might not go away for a couple of years (ditto).
Try those two resources. Good luck.
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