Satgen445  Satellite Antenna Tests 2 by GM4IHJ  (BID SGEN445) 4 Oct 97

For those seeking more information on using the very regular Wefax
satellites for 137 MHz antenna tests, the following is offered as a
set of simple notes. If however you are really interested in Weather
sats themselves , your questions should be addressed to either -
http://www.rig.org.uk  or http://www.drig.com   in England or, USA
respectively , which ever is appropriate.

Firstly the question of pre amplifiers. Omni directional antennas can
always be improved by adding suitable pre amplifiers between the
antenna and your receiver. They are not essential but they do help.

Satellites monitored have the following characteristics:-
NOAA 12 137.5 MHz is presently in an orbit which runs parallel to the
Dawn Dusk terminator line . So half or more of its picture is dark (
no sunlit) . This situation will not change for Northern hemisphere
stations until next summer. Meanwhile in the Southern Hemisphere Noaa
12 should give better pictures in what is now their spring/summer. 
NOAA 14 is in a much better orbit than 12 . Using 137.62 MHz its
afternoon orbits have brightly illuminated pictures , and the good sun
angle on the ground gives useful shadow detail in the pictures.
METEOR 3-5 on 137.85 MHz is not sun synchronous ( the Noaa's are ). So
its orbit plane shifts quite quickly . It has been giving good results
for Northern hemisphere stations in the mornings but is slowly getting
earlier each day and will soon be in a period of very poor early
morning or night time passes. At present this is already affecting its
pictures because of poor sun angle on the ground. So pictures are not
as good as those from Noaa 14. Equally important Meteor 3-5 is
automatically switching off when it is passing over ground which is
not seeing the sun. So Northern hemisphere stations will find that it
does not switch on until about 3 minutes after it comes above their
northern horizon. 
SICH-1 and OKEAN1-7 are both on 137.4 MHz. Sich-1 is a very rare bird
at IHJ, having been copied only once in the month of September, when
it passed far to the east early one morning. Okean1-7 is heard on most
mornings. But its transmissions are very brief, never more than 6 or 7
minutes , at which point it is switched off despite being a strong
signal in Western Europe. Passes intercepted have show ground pictures
of the White Sea and the area around Murmansk and Archangel. Two
pictures appear side by side and may be duplication, or perhaps a
stereo pair. Equally strange the pictures show only what is on the
satellites port /left side , not the familiar Wefax pictures of both
sides of the track.
NB. the noisy sats at 137.704 and 137.679 are Orbcom 1 and 2
respectively, sending digital data signals, not Wefax.

Meteor sat signals are generally stronger than those from the Noaa's.
Indeed while IHJ has no intention of becoming a Weather "expert", the
Meteor pictures offer a range of intriguing "picture DX" as you try to
see how far east and west you can get pictures from  Eg Foxe Basin and
the Ungava, westward,in the Canadian arctic, or Cyprus to the east.