NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Gps Crash
From: Dan Allen
Date: 1999 Aug 23, 11:19 AM
From: Dan Allen
Date: 1999 Aug 23, 11:19 AM
;From- Rodney Myrvaagnes [mailto:rodneym@IBM.NET] ;Sent: Saturday, August 21, 1999 10:20 PM ;To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM ;Subject: Re: GPS CRASH ;. ;. ;One disturbing thing I did note: The Lowrance lagged the Garmin by a little ;more than one second in its time display. Since they both must know the ;time to less than a ;microsecond to perform their location function, this ;suggests the firmware in the Lowrance is slow about updating the display. ;. ;. The display of time on Garmin receivers can be off by up to 2 seconds if the CPU is busy doing other calculations, and that is after the GPS is locked to the satellites. Before lock the time can have drifted by many minutes as the quartz oscillators seem quite inaccurate. My Garmin GPS40 (which is listed as needing a special button push to get a new almanac downloaded post rollover) has yet to work post rollover. It worked just fine through the rollover, but then a few minutes later it lost all satellites and I have not yet been able to get a fix with it! The 40 has always been terrible when it is "searching the sky" and trying to get its bearings from scratch, so perhaps this is just the same as the day I bought it. I'll try again more this evening. Dan danallen@microsoft.com
