Return-Path: Received: from imo21.mx.aol.com ([152.163.225.65]) by ns1.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-64832U3500L350S0V35) with ESMTP id com for ; Wed, 3 May 2000 11:57:01 -0400 Received: from ByronMFox@aol.com by imo21.mx.aol.com (mail_out_v26.7.) id k.64.253dafa (4199) for ; Wed, 3 May 2000 12:02:25 -0400 (EDT) From: ByronMFox@aol.com Message-ID: <64.253dafa.2641a790@aol.com> Date: Wed, 3 May 2000 12:02:24 EDT Subject: For you guys who do not have Differential GPS Good news. To: lancair.list@olsusa.com X-Mailing-List: lancair.list@olsusa.com Mime-Version: 1.0 <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> For you guys who do not have Differential GPS Good news. #1 : Effective at Midnight (GMT) on May 1, 2000, the Selective Availability (SA) : degradation feature of the Global Positioning System was discontinued. The : result is that the position and velocity information provided by GPS : receivers is now up to 10 times more accurate than before the discontinuation : of SA. No adjustments or upgrades to GPS receivers are required to take : advantage of the improved accuracy. : : Selective Availability (SA) is the deliberate introduction of error to the : precise timekeeping of the GPS satellites, thereby reducing both positioning : and timing accuracy for civilian users. It was designed to provide US and : Allied military forces with a navigational advantage in times of crisis or : conflict. : : This news is of particular importance to mariners, as the discontinuation of : Selective Availability (SA) will improve the predicted accuracy of GPS for : civilian users from within 100 meters (about 300 feet) to within 20 meters : (about 60 feet). In many cases, real-world users will find the accuracy to : be even better. : : Users of Differential GPS (DGPS), an error correction add-on to stand-alone : GPS, have already been enjoying positional accuracy in the 1 - 3 meter range, : so the discontinuation of SA will have little effect for those users. : However, the difference in accuracy between stand-alone GPS and DGPS has now : been significantly reduced. : : Additional information on GPS can be found at the Interagency GPS Executive : Board web site at www.igeb.gov. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML website: http://www.olsusa.com/Users/Mkaye/maillist.html Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>