Re: North Korea satellite: NOTAMs inconsistent withclaimedsun-synchronous orbit

From: Bob Christy (bob@zarya.info)
Date: Sun Apr 08 2012 - 21:55:36 UTC

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    Precise mathematical definitions are fine but there's reality to consider.
    
    One subtlety that people miss with a 'perfect' sun-synchronous orbit is 
    that the sub-satellite lighting conditions at a given location change on 
    a daily basis due to a combination of the eccentricity and inclination 
    of the Earth's orbit around the Sun.
    
    Another is orbital decay so if it an orbit is precisely and 
    mathematically sun-synchronous today, then tomorrow...... it isn't.
    
    Back to the NK launch - we seem to be seeing enthusiasm, ineptness or 
    whatever from Pyongyang that then becomes a propaganda item for the 
    other side. Reporters see black and white - the experienced among us see 
    the shades of grey and the patches of colour.
    
    Bob Christy
    
    On 08/04/2012 20:46, Brian Weeden wrote:
    > ............there is precise mathematical definition and that's good 
    > enough for me........
    >
    > On Sun, Apr 8, 2012 at 3:27 PM, Bob Christy <bob@zarya.info 
    > <mailto:bob@zarya.info>> wrote:
    >
    >     I agree absolutely. I made a similar point a few days ago, immediately
    >     after Ted's original analysis of the potential inclination (scroll
    >     down
    >     to the "Trajectory" heading):
    >     http://www.zarya.info/Gallimaufry/Kwangmyongsong3.php
    >
    >     Bob Christy
    >
    >     On 08/04/2012 19:57, Jonathan McDowell wrote:
    >     > ..........In the absence of an accepted international definition
    >     it's a matter of taste what the
    >     > tolerance should be. And for the North Koreans, if their
    >     satellite only works for
    >     > a couple of weeks, say, then you only care how much the local
    >     time drifts during that
    >     > period.
    >     >
    >     >   - in the spirit of friendly pedantic argument,
    >     >         Jonathan
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