From owner-freebsd-hackers Thu May 4 0:30:16 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from jason.argos.org (a1-3b058.neo.rr.com [24.93.181.58]) by hub.freebsd.org (Postfix) with ESMTP id 4EA5B37BFDD for ; Thu, 4 May 2000 00:30:04 -0700 (PDT) (envelope-from mike@argos.org) Received: from localhost (mike@localhost) by jason.argos.org (8.9.1/8.9.1) with ESMTP id DAA04098; Thu, 4 May 2000 03:29:30 -0400 Date: Thu, 4 May 2000 03:29:30 -0400 (EDT) From: Mike Nowlin To: Wes Peters Cc: Warner Losh , Matthew Dillon , hackers@FreeBSD.ORG Subject: Re: GPS heads up In-Reply-To: <39112085.DD0E6502@softweyr.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > This is what "Differential GPS" provides: a standard time source that > can be used to remove the SA meanderings from the GPS fix. If I'm understanding this correctly (with very little actual research into it) is that a DGPS station essentially transmits the difference between what it "hears" as it's location and what it's actual measured location is to the clients, which apply this change to their local "heard" position. (Assuming that both sides are within the appropriate range of each other that allows them to hear the same satellites.) Do I have it about right? (I just hooked up my Garmin GPS-20 and my Delorme Tripmate again to my "figure out what the differences are between these two GPS units are and plot them on the screen" program -- it'll be interesting to compare the results from now and 6 months ago...) Out of curiosity, how many people in this discussion are hams? --mike N8NVW (Funny how the GPS changes are two weeks after the FCC Part 97 licensing changes took place... I wonder if there's any (even remote) connection...) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message