[154460] in North American Network Operators' Group
Re: F-ckin Leap Seconds, how do they work?
daemon@ATHENA.MIT.EDU (George Herbert)
Wed Jul 4 19:15:26 2012
In-Reply-To: <20120704222927.GA19945@DataIX.net>
From: George Herbert <george.herbert@gmail.com>
Date: Wed, 4 Jul 2012 16:14:10 -0700
To: Jason Hellenthal <jhellenthal@dataix.net>
Cc: NANOG <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Jul 4, 2012, at 3:29 PM, Jason Hellenthal <jhellenthal@dataix.net> wrote:=
> Yeah but what you don't understand is that manual navigation after a
> certain point of difference becomes inaccurate to a degree that is
> unacceptable by most military standards.
Manual navigation (sextant, etc) is dead. It's not taught for new pilots o=
r mariners / navigators. A few hobbyists still learn that, but they can eas=
ily keep a solar-true time clock around if they wish.
Maintaining any time standard for that purpose is not supported. It's no re=
ason for the timekeepers, nothing we need to care about.
The few navigation systems that look at the sun and stars have - and inheren=
tly need - better time reference than the allowed 0.9 sec before we leap. T=
hey already handle this internally. That 0.9 sec max error comes to up to a=
bout 400 meters for equitorial surface nav or 6500 for orbital objects (or s=
uborbital - cough). Already unacceptable...
George William Herbert
Sent from my iPhone
