Re: North Korean Unha-3? Launch estimation

From: Marco Langbroek via Seesat-l <>
Date: Fri, 5 Feb 2016 10:56:53 +0100
Op 5-2-2016 om 9:47 schreef Jon . via Seesat-l:

> Some days ago some rumours appeared about a possible new launch of DPRK.
> Those rumours has been confirmed by NOTAMs and HIDROPACs.

North Korea's original letter of Feb 2 to the IMO on which these Area Warnings 
are based is here:

> Assuming a similar orbit than in previous launch and same Descending Node,
> the launch window would start the 2016/02/07 _at_ 01:26:03 UTC. Every day the
> rocket should be launched 28 seconds before than previous day for achieve
> same Sun-Satellite RAAN.

The 2012 launch was almost exactly 2 hours after Pyongyang sunrise. If that 
pattern repeats (pointing to a sun-synchronous orbit with daily overfly time 
around ~9h a.m. local time), launch will be around 00:24 to 00:41 UT rather than 
your 01:26 UT (00:24 UT if a similar solar elevation is aimed for; and 00:41 UT 
if they merely aim for 2 hours after Pyongyang sunrise).

There is also some indication that the timing of the 2012 launch was (at least 
partially) dictated by a suitable window lacking overflights by western 
reconnaissance satellites.

The launch window starts around local daybreak and ends just short of local 
noon, indicating a desire for an orbital plane resulting in morning passes.

See also

- Marco

Dr Marco Langbroek  -  SatTrackCam Leiden, the Netherlands.

Cospar 4353 (Leiden):   52.15412 N, 4.49081 E (WGS84), +0 m ASL
Cospar 4355 (Cronesteyn): 52.13878 N, 4.49937 E (WGS84), -2 m ASL
Station (b)log:
Twitter: _at_Marco_Langbroek
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Received on Fri Feb 05 2016 - 03:57:17 UTC

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