1 On a stationary GPS without a differential correction signal, you
2 should see a 20 m average radius "drunken walk" pattern. On the same
3 receiver with DGPS corrections and a good view of the sky, the
4 error the same receiver with DGPS corrections and a good view of
5 the sky, the error should be reduced to approximately 2 m average
6 radius. If you've always wanted to know exactly where your house
7 is located without that annoying GPS "wander," but didn't want to
8 spend the money for a DGPS radio, here is your big chance!
10 I'd like to announce a fun DGPS hack. I've written a small Un*x
11 server and client for redistributing DGPS correction signals over
12 the Net. Basically the server grabs the serial byte stream from my
13 DGPS radio and sends it off over a TCP connection. The client does
14 the same thing but in reverse. The result is that you can receive
15 the local DGPS corrections from absolutely anywhere by using the
16 Internet as the world's largest extension cord. You'll still need
17 to be within 1000 miles or so of San Francisco, California, USA
18 for best results. However chances are better than not that the GPS
19 error will still be reduced if you are 2000 to 3000 miles away.
20 Several respondents from 2000 miles away have noted that the remote
21 differential signals have diminished the SA induced position and
22 velocity errors by approximately 3x.