Satgen 592  An Ill Wind  by GM4IHJ  (BID SGEN592)    2000-07-29

Terrestrial DX operators and satellite sub horizon chasers, will not
need to be told that July 2000 has already featured some intense
solar activity. Solar flux has headed back up to 250+, which should
mean superb DX conditions. But it has not quite turned out that way ,
as massive bursts from the Sun, have sent the Earths upper atmosphere
ballooning outwards. A situation which spreads the ionosphere ever
more thinly upwards, rendering it far less useful for returning HF
radio signals back to earth.

However, radio amateurs troubles in this respect, have been minor
compared with the shock to ASCA the Japanese Xray satellite. The
blast that hit ASCA and sent it spinning out of control, appears to
have occured somewhere near its 400 km perigee passage. When a sudden
increase in atmospheric drag sent it tumbling end over end. In
consequence of which its solar cells no longer faced the Sun, and
with power thereby reduced to near zero. Its onboard house keeping
computer, shut the satellite down. So now the batteries are cold and
need sunlight on their section of the satellite, if they are to be
warmed up before they can be recharged. Then, the satellite has to be
reorientated to get maximum sunlight on its solar panels for the
battery charge. Two, far from simple tasks.

Meanwhile on the Amsat front. RS13 was sending signals back to
Scotland as it flew near the south pole , or passed down the Pacific
east of Chile, on one or two passes each day up to 14th July. But as
the Solar fireworks started, all sub horizon returns ceased until
19th July. When, in a total reversal of form, 5 successive south
polar passes put signals into Scotland. But this was not repeated on
subsequent days, which reverted to the previous pattern of one orbit
with signals per day.

Indeed , even these recent passes have been unusual. In that they
have had all the wide band , spasmodic broken signal patterns ,
rarely seen from the south, but frequently seen on north polar tracks
on the FFT DSP AF Spectrum display during auroras. A signal pattern
which is discontinuous, wide band , often 80 to 100 Hz wide. Looking
like a row of thick vertically staggered roof tiles or, computer back
slashes.

>From which a new form of auroral warning seems to be available at
IHJ. Whereby, on 22nd July. The back slash / slabbing  roof tiles
auroral signal pattern appeared on the FFT display as the RS13
satellite passed the south pole at about 1740z. At which point it
dawned on this reporter that perhaps , if the south polar ionosphere
was strongly auroral, the north polar ionosphere might be similarly
auroral. 

A quick check of Scandinavian 48 MHz TV , revealed that north and
south were indeed in synch. With wideband back slashing signal
patterns coming up from the south, as very strong auroral TV came in
from the north.