[Moon-net] [Moon] Iono absorbsion or Unusual Libration??

[Joe Taylor]

Hi Peter,

I commend to you the "Moon Libration Applet" at 
http://www.jgiesen.de/moonlibration/index.htm .

Illustrative graphs on that page do indeed show that the 
Libration latitude reaches a minimum near the end of October 
2007 (Oct 28), and Libration longitude reaches a maximum 
maybe two or three days later (Oct 30 or 31?).  So yes, 
lunar libration motion was near a minimum this past weekend.

Of course, libration fading of EME signals depends on the 
full EME path geometry including the locations of 
transmitting and receiving stations on Earth and the 
topocentric positions of the moon as seen from the two 
stations.  The "nodes" or minima in fading rates will not be 
the same for all station pairs at the same time.

	-- 73, Joe, K1JT

peter blair wrote:
>  Is there anyone out there who can calculate the time of Libration 
> nodes? Thats when the  rocking  motion between moon and earth becomes 
> very slow and so the fading rate also slows right down. A  Libration 
> node would be the " Occams razor" answer to what we noticed last night. 
> It would fit with the slower deeper fades on 432  and the relatively 
> short ( ~1  hour) duration.
>  It would just be interesting to know!
> Did any 144 MHz people notice the same effect ?
>  73 Peter G3LTF