From owner-freebsd-hackers Wed May 3 19:31:12 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from rover.village.org (rover.village.org [204.144.255.49]) by hub.freebsd.org (Postfix) with ESMTP id 1AEC337B84B for ; Wed, 3 May 2000 19:31:09 -0700 (PDT) (envelope-from imp@harmony.village.org) Received: from harmony.village.org (harmony.village.org [10.0.0.6]) by rover.village.org (8.9.3/8.9.3) with ESMTP id UAA22432; Wed, 3 May 2000 20:31:07 -0600 (MDT) (envelope-from imp@harmony.village.org) Received: from harmony.village.org (localhost.village.org [127.0.0.1]) by harmony.village.org (8.9.3/8.8.3) with ESMTP id UAA36034; Wed, 3 May 2000 20:30:48 -0600 (MDT) Message-Id: <200005040230.UAA36034@harmony.village.org> To: Matthew Dillon Subject: Re: GPS heads up Cc: hackers@FreeBSD.ORG In-reply-to: Your message of "Wed, 03 May 2000 16:13:40 PDT." <200005032313.QAA65552@apollo.backplane.com> References: <200005032313.QAA65552@apollo.backplane.com> <200005031744.KAA63550@apollo.backplane.com> <20000503200006.A35116@cichlids.cichlids.com> <200005031957.NAA01354@nomad.yogotech.com> <20000503130759.A15403@orion.ac.hmc.edu> <20000503221528.A37472@cichlids.cichlids.com> <20000503151513.D337@beastie.localdomain> Date: Wed, 03 May 2000 20:30:48 -0600 From: Warner Losh Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In message <200005032313.QAA65552@apollo.backplane.com> Matthew Dillon writes: : No, you can't just average several measurements w/ SA on and expect : to get any improvement. SA isn't just 'noise', it's like a : drunken walker. All you get when you average several measurements : is the location of the drunk. The SA can be averaged out, but you need to have another source of time as well as GPS. GPS alone will give you a grid square you are in, but the nature of the pseudorandom noise is such that you don't get a nice sine wave (collapsing for a moment to 1 dimention). It is much more distorted than that. Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message