This has very little LBC content, and if you're not the least bit
interested in the satellite topic, I'd just delete it right now!
Just for fun, here's a link to glonass (global navagation satellite
system). Your enemy (USSR) has to have one too right? While reportedly not
as accurate as the GPS, it has no selectively introduced error, why? Their
"enemy (US)" had gps so why bother with figuring out how keep them from
your signal :)
http://mx.iki.rssi.ru/SFCSIC/english.html
My america's cup friends were into glosnass several years ago. Now in many
locations they can use "differential" GPS", basically the the addition of
a radio transmission from a "known" location (like a light house). These
signals are provided by the USCG and other maritime organizations. The
concept is same as the very similar to LAAS and WAAS that were mentioned
several posts back for aviation.
The US DOT is now agumenting the USCG stations with other stations on the
land to get full DGPS coverage of the US. The forest service also has a
bunch of DGPS stations. Before you freak out that now any one can
accurately bomb us, the DOD can still change the selectively introduced
error signal much worse than normal if they suspect an attack is
happening. Of course they can still get a good signal!
Anyhow, here's a cool link about a way you can use the Internet to
receive a differential signal...
http://www.wsrcc.com/wolfgang/gps/dgps-ip.html
Trucking companies use a differential based GPS system to know where the
cargo is at all times. It uses cellular to update the trucks position at a
fixed interval. You think truckers like the company knowing how much time
it took to go from point A to B? Lots of trucks have these receivers, it
looks like a "squat mushroom" about 12 or so inches in diameter, sometimes
it is "hiding" under the wind deflector on top of the cab.
Now for LBC content :) This weekend, I used my cheap gps setup ($79
reciever) with my company provided laptop to look for a new house. It's
very easy to find the shortest path between a bunch of addresses using a
mapping program and then use the gps to keep you on the route. BTW: My gps
"driver" software had a y2k problem!
Unfortunately, I couldn't go on this house hunting trip in my 77B because
I haven't finished "Re-toxing" it for my new states emissons :( I have
finished putting on the new springs (front and rear), tie rods,
poly/rubber bushings, shocks, droop limiters, etc on though!
Can't wait to start driving it again... Soon now!
-craig
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