[LEAPSECS] GPS certified for navigation?
seaman at noao.edu
Thu Sep 23 16:00:09 EDT 2010
Ah! Much simpler than http://bit.ly/bwkyGC
...and sextants are even usable while in motion: http://bit.ly/aiWlyf :-)
Isn't the point of many of the issues you describe that you may *not *get what you paid for?
"Ability to notice errors" - now there's a phrase to inspire confidence!
On Sep 23, 2010, at 12:35 PM, Steve Allen wrote:
> On Thu 2010-09-23T11:59:33 -0700, Robert Seaman hath writ:
>> What precisely is the status of GPS for actual purposes of navigation?
> You are in a twisty little maze of bureaucratic regulations, all alike.
> You get what you pay for in GPS. There are significant differences in
> the abilities of receivers to notice whether they are receiving
> signals that are self-consistent.
> In the long run, there's intentional problems like theater-level
> spoofing (which the US military have used for years, as,
> unfortunately, noticed by the Keck telescope control timing systems)
> For ability to notice errors see RAIM
> For IFR aviation in the US the FAA has technical standard orders
> TSO C129 (A1) and TSO C129 (A2)
> describing the requirements.
> for robustness against the ionosphere (mostly for surveying) see WAAS
> For marine traffic in US harbors the Coast Guard requires AIS
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