NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Role of CN at sea
From: Dan Allen
Date: 2004 Oct 13, 08:40 -0600
From: Dan Allen
Date: 2004 Oct 13, 08:40 -0600
-----Original Message----- From: Navigation Mailing List [mailto:NAVIGATION-L@LISTSERV.WEBKAHUNA.COM]On Behalf Of Frank Reed Sent: Wednesday, October 13, 2004 12:35 AM To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM Subject: Re: Role of CN at sea, was RE: Averaging sights ... Frank Reed wrote: There is an ambiguity in the above Q&A that may be worth pointing out. The obvious interpretation is that a sailor should carry a spare GPS receiver onboard in addition to the main GPS system. Dan Allen replies: I have had a Garmin GPS40 receiver simply die. I had one on the dash of my car driving across eastern Washington. It was on and tracking satellites just fine. Then, it froze. Nobody touched it, and it had new batteries. Pulling the batteries out (hard reboot) did not fix it. It never came back to life. Garmin had to replace the unit under warranty. A friend of mine sailing from San Francisco to Hawaii and although he knew CN, he instead took 4 separate GPS receivers as his means of redundancy. But what if the same kind of electronics failure that hit my GPS40 years ago hit one or more of the GPS satellites themselves? Does anyone know about actual mortality rates of the US GPS satellite system? Dan Allen N 39d 59' 50" W 111d 45' 27"
