[amsat-bb] Observations of arissat signal at 52.48 degrees North

[andy thomas]

Guys and gals

I have a modest setup here observing Arissat-1 with a yagi fixed in azimuth and elevation and automatically reording. The sstv signal is detectable without a one transitor preamp but only reproducable with it.  The most important thing about the 
setup is the orientation of the receive antenna. It is pointing at 
approximately 210 degrees and is fixed.

You might ask why not set it at the aizmuth of the maximum elevation, which is what I always do for 
telemetry cubesats. First of all my answer is that I get 
better pictures at this azimuth. Secondly as I said to Colin G1IVG I think I know 
why.

If you go to the front page of my 
website http://www.andythomas.eu and scroll down you'll see a sequence 
of photos I took of the ISS as seen in my telescope. I was surprised how the attitude of the spacecraft changed as it approached 51.6 degrees 
(the orbital inclination and therefore the maximum latitude 
subsatellite), then went away relatively southbound (and of course 
eastbound). We are at 52.48 degrees North. My thesis is that Arissat-11, which is on more or less the same orbital inclnation, exhibits the same change in attitude as it reaches 51.6 latitude, relative to us, so the 
antenna is not shielded and therefore the signal level peaks. As the signal level is marginal I can detect this slight improvement.


I've sent a copy of this to theWelland Valley ARS for comments and would appreciate your comments too.

73 de andy g0sfj