NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Dependence on GPS
From: Peter Fogg
Date: 2009 Oct 31, 15:51 +1100
--~--~---------~--~----~------------~-------~--~----~
NavList message boards: www.fer3.com/arc
Or post by email to: NavList@fer3.com
To , email NavList+@fer3.com
-~----------~----~----~----~------~----~------~--~---
From: Peter Fogg
Date: 2009 Oct 31, 15:51 +1100
frankreed wrote:
and then:
Until they don't work. Also known as the failure of the technology of dry pouches. For example.
I think your first point stated the position best, Frank. Technologies are just waiting for an excuse to not be reliable.
No, that FOR A VARIETY OF REASONS not one was available for use at the one time.
Not quite the same thing as "failure", since some of the reasons had little or nothing to do with the GPS system, and were related to "failures" of other systems.
To make this point again: GPS depends on having power, and a reasonably dry environment, and a functioning antenna, and an extent of lack of abuse, and/or enough dry cells ( we call 'em batteries) over what could be extended period, etcetera etcetera.
My experience of the joys of sailing are that all too soon systems develop problems. Its a harsh environment, especially for electronic equipment, full of the slings and arrows of outrageous fortune, damp and subject to repeated nasty shocks in most directions at what can seem like the same time. Once again, a little water over the sole can soon lead to the failure of many of the boat's systems, and can happen all too easily.
You're missing my point, Frank.
All technology fails.
and then:
Those dry pouches work, for example.
Until they don't work. Also known as the failure of the technology of dry pouches. For example.
The spare should be a different make and model and stored in a different way from your main receiver to avoid the trap of identical failure modes. It should also be stored in a small metal case to serve as a Faraday cage.
I think your first point stated the position best, Frank. Technologies are just waiting for an excuse to not be reliable.
prepared for that failure by carrying a spare GPS receiver. Peter tells us that he has had multiple GPS receivers all fail all at once.
No, that FOR A VARIETY OF REASONS not one was available for use at the one time.
Not quite the same thing as "failure", since some of the reasons had little or nothing to do with the GPS system, and were related to "failures" of other systems.
To make this point again: GPS depends on having power, and a reasonably dry environment, and a functioning antenna, and an extent of lack of abuse, and/or enough dry cells ( we call 'em batteries) over what could be extended period, etcetera etcetera.
That kind of astronomically improbable bad luck seems to strike certain people, but it's not the sort of thing that could be considered normal.
My experience of the joys of sailing are that all too soon systems develop problems. Its a harsh environment, especially for electronic equipment, full of the slings and arrows of outrageous fortune, damp and subject to repeated nasty shocks in most directions at what can seem like the same time. Once again, a little water over the sole can soon lead to the failure of many of the boat's systems, and can happen all too easily.
Only an electical shock could kill multiple receivers at once under normal rules of "luck", and to defend against that possibility the solution is to keep your spare GPS in a metal box to serve as a Faraday cage (does anyone sell this as a standard item?). But beyond receiver failure, there's a much less likely yet still important risk that the GPS signal itself might fail. There are cases where you might have a somewhat degraded position accuracy if one or more satellites fails, but those are temporary conditions and apparently very rare. Of greater concern is the prospect that GPS signals might be jammed over some region, perhaps dozens of miles in extent, for a military or criminal purpose. I'm not talking about a direct military assault ..
You're missing my point, Frank.
--~--~---------~--~----~------------~-------~--~----~
NavList message boards: www.fer3.com/arc
Or post by email to: NavList@fer3.com
To , email NavList+@fer3.com
-~----------~----~----~----~------~----~------~--~---
