Wednesday
13th January
From
John Storey.....
This
morning we put Jessica's nylon snow cover on the sodar antenna,
attached all the little springs that hold it down, and spent
a couple of hours taping up all the little holes where ice
crystals might get in. It now looks exceeding smart with aluminium
tape everywhere and the handsome colour-coordinated silver
nylon cover. Webcam devotees will already have noted that
the antenna is now installed in pride of place on the roof
of the AASTO, just to the right of the entrance door. (By
the way, "sodar" stands for sonic radar. The data
reduction package is called SOD_IT. Or at least, if it's not,
it should be.)
Lurking
under that shiny cover are 52 piezoelectric transducers (the
infamous "hooters") that can generate a sound level
of 87dB 200metres away. Fortunately the beams are sent straight
up or 30 degrees from the zenith. The sidelobes that come
out horizontally at ground level are 40dB down, which is still
loud but not offensive. It can't be heard inside the MAPO
or ASTRO buildings, and is *just* audible from the cargo area
in front of the Dome. However, it is a tad noisy *inside*
the AASTO...
By
early afternoon we had it merrily beeping, singing its little
heart out with the sodar song. We seem to be measuring to
600 metres altitude without any problems, which is just beaut.
It's also hooked up to the supervisor computer via port 2006.
We can talk to it via telnet, but have the "Narrabri"
problem that the frog-DOS wants to interpret the RS232 bytes
in its own peculiar way. Daniel says that mcba can fix this
particular problem in a flash, and possibly already has in
a pharlap script somewhere. We await instructions.
It
looks like the simplest thing is to leave the sodar powered
up the whole time. The noise could then be turned on and off
via a cron script on pharlap. The only disadvantage of this
is that the hard disc on the IBM laptop will be running continuously.
I confess to not having gotten around to designing a remote
on/off switch, but did throw a passing glance at the switched
110V outlet on the back of the webcam.
Speaking
of which, the webcam is working brilliantly, but the temperature
in its little housing is up to 34C. Does anyone know why this
might be? There's also only one perspex dome in place - I
guess that's fine but not quite as energy efficient as with
two.
Abu
has now been switched off as it's clearly not going to get
cold enough. Al Fowler is walking around looking depressed,
waiting for Al Harper to turn up with the new cold head.
I've
recorded the sodar song on my Mac in preparation for creating
a .wav audio file on our home page. This will allow folk around
the world to experience the delight and pleasure of an optimised
echo-sensing tone sequence. Ambitious web surfers may also
like to play it through their hifi at terrifying volume, thus
truly recreating the sodar experience and provoking involuntary
flight instabilities in passing birds.
Peter
Gillingham has spent the day machining up new pieces for the
tip-tilt secondary. He's resurrected the incorrectly made
Invar backing plate that everyone else said would be too much
work to fix. Peter has also cast his expert eye over the G-tower:
"mostly good, but the stiffness is compromised by the
poor pin-joints at the end of the struts". He's even
come up with what I consider to be the most plausible theory
so far on why vibration is mysteriously coupled from the MAPO
building to the SPIREX telescope - as a sheer mode through
the long canvas strips that seal the floor.
Meanwhile
there's been an outbreak of graffiti on the wall of the solar-powered
dunny, as various people attempt to prove or disprove the
existence of god. The alt.toilet.religion discussion group
has yet to go on-line.
The
18th to 26th no-fly period appears to be a reality, and confronts
me with the difficult choice of leaving the Pole early before
everything's finished, or getting home too late to stop the
School of Physics collapsing in a big heap. Unless a major
problem occurs in the next couple of days, I think I'll leave
here on Saturday (there are no pax flights on Sunday) in the
hope of catching the last flight to ChCh on Monday the 18th.
We
had another tour of the AASTO by folk from the AGO (Automated
Geophysical Observatory) project. They were very impressed
with our instruments which are clearly lots more fun than
geophysical ones. They were completely blown away by Melinda's
24 hour webcam movie which demonstrates, unequivocally, that
we are at the South Pole. They said I should make sure Melinda
makes another one - maybe several so we can pick the best
one - very soon. (Actually I'm making that last bit up.)
John
Wednesday
13th January
From
Michael Burton.....
Greetings
from the Pole!
Coming
towards the end of my first full day here now. After 4 days
in Christchurch things moved fairly quickly and I was through
McMurdo with just an overnight and down to Pole. Temperature
a mild -30 right now, and sunny conditions, though I have
to say I haven't quite acclimatized as yet! The altitude always
hits you when you first arrive, but by tomorrow I hope I will
have adjusted and feel like some real work.
The
delays in ChCh meant I missed the Scott's Hut race in McMurdo
by 1 day, and also the most fabulous ice-halo display. The
locals believe it may even be a world record for the most
number of different halo forms (24) ever seen in a single
display - have a look at www.spole.com (which will be up about
half the day for you) to see some of the spectacular shots
of what ice particles high in the atmosphere can produce.
Pole
is as crowded as ever, with many new experiments, and some
of the old, all sharing the space, together with a large complement
of construction crew who are starting work on the New Pole
Station (a 5 year project). I came down with 2 of my students,
and John Storey and Peter Gillingham (AAO) are also here.
We seem to have got one of the expts going (a SODAR, or acoustic
radar) but there are some major problems with the infrared
camera at the moment.
I
must admit the sense of adventure coming here is not quite
what it was in the past, this being my third trip now, but
it still is an incredible place and we are a long way from
home. 2 sets of adventurers have passed though, a French expedition
who were on the final leg of the '3 Poles' (Everest, the North
Pole and the South Pole) having skied here from Berkner Island,
and a Dutch group who paraglided here (attach sails to your
sleds). The latter group are actually trying to cross the
continent and end up in McMurdo, but are probably too late
already, and are looking like they need to be rescued! And
we are expecting a Kiwi expedition
in a few days, lead by Peter Hillary, Edmund Hillary's son
(who was, of course, here in 57, as well as in 97)
Michael
 
|
Further Information
|
Contact:
| 
