Actually, the US Government can turn SA on at any time...I wouldn't say they "disabled it". -marc On 21/4/03 11:35, "Chris Loiacono" wrote: >> >>> If you are out on the ocean then >>> you are probably stuck with regular GPS, which has a >> position accuracy >>> of 15 meters 95% of the time (assuming no SA) > > Back in '72, the worst case gov't studies showed 15m or better. > Concern that US enemies could use this accuracy against US installations > caused the introduction of SA, while the US military maintained 15m res for > themselves. > US Gov't disabled Selective Availability in May '02. > There are have benn tests done that show avaerage accuracy is now about 6.3 > m without SA. > > >> If you're out on the ocean, can you tell the difference >> between this spot, and that one 50' away? > > Divers, both recreational and commercial have a great interest in such > accuracy. Try swiiming againsta current with a limited air supply to get to > a particular spot underwater. Consider those who regularly deploy & retrieve > various kinds of sensors from the ocean floor, or perhaps even a crab trap > that has lost it's float...... > > c > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > -------------------------------------------------- Marc Nicholas Geekythings Inc. C/416.543.4896 UNIX, Database, Security and Networking Consulting -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu