Extracts from Rodney Mark's South Pole Reports, 1994
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Nov 14
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hi all,

I finally made it, not without some lvery last minute delays (fuel leaks
etc), it's quite bewildering the first few minutes after you get off
that plane, especially at 6am after no sleep!. Temp was -39C yeasterday,
and about -34C today....pretty hard to describe the feeling, but the
overall effect strikes me as somewhat like being on the moon!
Better make this a short message as the link is not too good, the only
reason I'm logged in here is that the local net is down!!! so I can't
log into my own computer unless I want to walk out to CARA.
Briefly, I've met Bob Pernic and the CARA crew, had a look out there at
the IRPS etc. Bob plans to move irps into the cara building in the next
few days, then we will start working on it. He has a good spot planned
for it, with good acces to the roof,etc, and near to jamie's other
stuff.

Nov 16
======

Hello all,

Weell I think I'm pretty much getting used to this now, getting into a bit 
of a routine. I haven't really suffered from altitude problems at all, 
although a few people have been pretty sick, it seems to strike at random.
The weather is beautiful and clear, and a bit cooler today at -41C, 
although to be honest I can't really tell the difference between this 
and the -35C we had yesterday. The harsh landscape that greets you on 
arrival softens as you get used to it, and you can appreciate it more...
especially from the top of the Met Tower - I highly recommend that you 
find some excuse to go up there and tinker with the microthermal sensors!

The news on the IRPS is that there is no news, it is still waiting to be
moved to the new building. This may happen this afternoon but i WOULDN'T
count on it. It's fairly chaotic out in the dark sector at the moment, as
the ASTRO people have started arriving, wanting to take over their building
asap, while the CARA people are still getting theirs built! A lot of this
is a result of the flight delays and so on, apparently everything is a week
or two behind schedule, since there have only been about 15 flights
in out of a usual 40 up to now.

My stuff is coming along okay, I've fixed up some problems with the "kite"
experiment John Briggs had, and started gearing it up for telemetry based
collection. To this end I have managed to scrounge a new, totally unused
and unwanted ICOM receiver, which we may be able to keep for the season if
we're lucky! With luck this will mean we can run the experiment from this
cosy office in the clean air building, rather than trying to find space
in the overcrowded balloon launch tower.

I've also met our winter over, Chris Clevelin, who is a nice guy, however
he seems to have a very large number of projects to run next year.
That's about all for now, more news as it comes to hand...

Bye for now,
Rodney

Nov 19
=== ==

hi again from the sunny south, where today we have a pleasant and windless
-38C, still too cold to hang around outside for long, but nevertheless it
has a summery feel to it!
I've been a bit engrossed in my work the last couple of days to take in
much of the scenery, except for watching a plane take off whilst at the
top of the Met Tower...they really do seem to have to strain those C-130s
to get them off the ground here on their skis, they don't really get much
speed up and the air is quite thin, so they don't get much lift; this plane
just seemed to hover along a couple of metres off the ground for a fair
while trying to will itself into the air! I was talking to one of the
pilots in mcmurdo and he said that going to higher and colder places on the
plateau with no ski runways at all, dropping off these AGOs for example,
was a very delicate situation indeed in a large-ish sized plane.

The IRPS has now been moved out of ASTRO and into AMANDA/CARA..., not a big
job really, but one which really lets you know about your reduced capacity
for heavy lifting up and down stairs here! The A/C building is still full
of carpenters electricians and painters, and it's not really going to be
easy to set it up on the roof at the moment, so I will probably content
myself with getting it going inside and doing the requested calibrations.
It hasn't been reassembled yet, but I will probably start on that tomorrow,
since my other work has reached a point where I'm waiting for some advice
from the chaps in Nice.

On the microthermals, I have got the sonde experiment to the point where it
will work reliably with the IC7000 here on site. This is a positive piece
of news for us, obviously! What remains to be done now is link this with
the simultaneously transmitted Vaisala weather sonde data. The NOAA (ozone)
people do a very similar kind of experiment, however the operation of their
experiment is far from transparent, to say the least. They use a
modem/decoder which appears to handle the two signals at the same time, one
of which I have also lain my hands on. However I have no idea how it works,
nor do the NOAA staff here, and there is no documentation that I can find.
I might send some more details as part of a separate message, to those who
think they may be able to help (e.g. mcba :). The source code used to run
their data acquisition is not here either, only executables. Seems the
people who designed the experiment don't want anyone to mess around with
it!

Bye for now,
Rodney


Nov 23
======

Hi all,

Well time seems to be flying by at the moment, now I only have about five 
days to go. The weather is still calm and sunny most of the time, 
around -38C - it hasn't moved more than about 3C from that since I 
got here. I'll be leaving around sunday or monday, which means I'll 
be here for that great American tradition - Thanksgiving! Looks like 
being a pretty lively saturday night.

I'm making some progress with the IRPS, it's connected to the vacuum 
line still, and I'm ready to start cooling it down. The only thing 
holding me up at the moment is all the construction work going on 
at AMANDA/CARA at the moment...I couldn't get near the IRPS this 
afternoon because they are polishing the floor!! Hopefully things 
will be a bit less chaotic when you guys get down here.
Bob Pernic has been very helpful, he's got one of his engineers 
helping me to make sure I don't blow anything up while using the 
vacuum pump, and with cooling it down, etc.

So, the state of the IRPS is as follows:
It has been pumping down for around 48hrs now, and is holding a 
steady vacuum of 2-2.5 10^-5 torr.  The irps program is working okay, 
the temperature check program etc give numbers which make sense when 
compared to entries in the log book (see below). The IRPS cannot be 
connected to the internet until the fibres, connections, etc. are all 
in place, which they are working on now. There has been 
internet access to CARA, using cables run from the ASTRO building, 
but unfortunately, due to an unfortunate meeting between these cables 
and a large bulldozer ploughing through the snow, the building is off 
the net completely and indefinitely. Hence my new address!

As far as the microthermal stuff goes, it doesn't look like I'll be able 
to resolve fully the reading of the vaisala sondes before I leave, so 
I am contenting myself with checking the capabilities of the CT2 sondes 
themselves (which are working) i.e. their reliability in outside 
temperatures, calibration and eqilibration etc. and I'm going to 
attempt to send one up on a small kite someone has here, although it 
may be a bit too small. I've also been doing various calibrations on 
the mast to tidy up the loose ends of that experiment, and make sure 
that the data we have are as accurate as possible.
Also checking out the balloon launching methods and equipment they use, 
everyone (particularly the winter overs, the ones that really matter!) 
is very cooperative, and I don't think we're going to have any problems 
with that side of things.

All for now,
Rodney.


Nov 24
======

We started cooling down the IRPS last night, and it's going without a 
problem. I expect to have the inner can solid today assuming it goes 
smoothly, so you can go ahead and send me the promised intructions 
about setting it up for taking data. I'd like to make a start on it 
today if possible. By the way, we could not find the black paint you 
specifically mentioned, but do have some other stuff which is supposed 
to be "ultra flat" black, hope that will work okay.

cheers,
rodney


Nov 24 (part 2)
===============

Well, I have pumped the inner LN2 can down to solid, and the whole thing
seems to be holding topgether pretty well, the outer can doesn't 
need too much topping up. The detector temperature is sitting at around
72-72K, and the dewar vacuum is down to < 1 10^-6, pretty good for
your average dewar so I gather! I have now disconnected the turbo pump,
to see how well it holds for awhile.

Rodney.


Nov 28
======

Sorry I'm late getting back to you about the irps, but I can make up
for it with lots of good news! Part of the problem is that I'm working
on it till late at night out there where there's no internet connection.
On the subject, they are working on that at the moment, there should
be a connection within a few days.

I have finally got the fet balance figured out, using p 1 and gb to 
look at the ramps. I didn't really know what I was doing to start with,
so it was a long tedious trial and error process to figure out that
the detector leadscrew was in the wrong position, and that the fet 
balance was several revolutions out. However I've got that figured
out now, and it is, as you say, quite easy to get close to that minimum
positive ramp. The detector noise at 72K is quite low, < 0.1V (is that
low??).

The problem I mentioned with the aperture/filter calibration is something
I've noticed quite frequently in the log book as well actually. It's more
the aperture, I think, which sometimes goes to the wrong place, eg sa55
might give you the 2.8 or blank aperture. But after a few tries, or maybe
restarting the program, it will work. It does not appear to go off once it is
calibrated. The only error message in this part of things is an occasional
#141 with zf. 

I have wired up the BB source sensor and it appears to work fine, giving
a reading of around 30C, which IS the actual temperature in there,
almost insufferably hot in there after awhile, so don't complain to
me about Sydney! :)

I also have the rotator/mirror connected, so I'm ready now to flash the 
detector, so if this works out okay you'd better send me the next
installment of the recipe. I assume with the noise measurement I just
take an average of several p 1 readings at balance, then go a bit more
positive, repeat, and find the slope? Is it important to do this
very precisely?

And finally here is the irps startup message:

IRPS version 1.5
calibrating machine speed.............. loops for 1 ms = 1250 (e.g.)
[...same again...]

opening <..\log\irpslog.xxx>
command = READ_FILE

taking input from file <IRPS.ini>  command = INTERRUPT


Cheers.
Rodney


Nov 30
======


Well I've had a frustrating but ultimately useful night battling with the
irps - there certainly are some things about this instrument that seem
quite flakey, especially to the novice, but nothing life-threatening...
so far!

I arrived at a good fet balance, and flashed the detector, at which point
ALL of the motors gave up the ghost, i.e. aperture filter and mirror.
This problem was solved (as many are) by rebooting the computer and
restarting the irps program. That is not to say the previous problems
with ap./filter were fixed; just that I could make the motors go around
and line them up by eye again. By the way, the rotator command "sr"
(move to a set position) does not work - it just tries to vibrate
itself to death (no error messages) - but "str" (just move around)
works fine.

At this point the fet balance started behaving very bizarrely, showing
ramps from negative saturation to noise, finally settling on a sort
of distorted sine wave which persisted through several revolutions
either side of the previous balance point. I eventually lost this
point in all the to-ing and fro-ing, and decided to look at the BB
and fluoro source just for the hell of it. All of the commands here
seemed to work perfectly well, even getting the CV filter, and so 
I ended up with a nice preliminary BB spectrum. It is fairly simple
to adjust the gain, look at the ramp etc., and I think tomorrow I will
be able to get some real data. This seems even more promising since,
at the end I put the blank aperture back on, and lo and behold there
was a nice positive ramp, much less noisy than before, which was
easily adjusted down to the required flat region...it was more than
a revolution out! After this adjustment the required gains for
the BB and different apertures also decreased, thankfully since I was 
nearly at the limit.

So, all this rambling aside, I'll be able to get some data, but it
might be good if you could further prioritise your wish list; the
minimum K-band BB and fluoro with the 1mm and 2.8mm apertures should
be okay (mcba's further complications notwithstanding!), but I may not
have time to do everything. I have said I will leave thursday, but
will undoubtedly be pushing that back to friday. Bob Pernic is leaving
on Saturday, it might be difficult to stay longer than him since I was
supposed to leave a week ago.

Well that's all for now, goodnight
Rodney.


Dec 1
=====

Well, there was no fire.
So, I have taken a heap of BB spectra at 5 temperatures from 0 to 65C (the
coffee maker didn't get any hotter than that!), with the 1.0mm and 2 2.8mm
apertures, broadband fluxes through the j,h,k,l amd m filters at most of
these temperatures, and arc spectra through the 0.4, 1.0, 2.8 and 4.0mm
apertures. The spectra look good to me, very smooth although there is the
occassional small hump, perhaps due to stray light hitting the detector?
I was a little inconsistent with the use of gain/timing settings, but 
all of the spectra have high S/N - the worst case being about 1% error
in flat bits at low temperature. The flux was very low in some cases, and
I had to make some concessions to time. Some of the arc spectra have nice
sharp peaks as well. The logfile in question is about 95K, seems a little
small, hopefully it's in some sort of compressed binary format, and I haven't
lost any data!
If I manage to send the file, it will appear in ~rdm/irps/.
Well I think I'll be leaving tomorrow, just when it's starting to warm
up, too! Only -28C at the moment.

See you sonn,
soon that is,
Rodney


Dec 2
=====

Yep, I'm leaving today, well hoping to, except now it's the same old story
with the broken planes...
I'm going to miss the big visit from the head of the NSF tomorrow - a lot
of surface cleaning going on for that...lots of people moving dirty 
looking pallets out of sight, grooming the snow at the front of the dome
etc. This guy is coming to open the CARA building, the Pomerantz building
as it is to be known - he is staying for a total of four hours, so they
will be keeping the plane running out on the skiway for that entire time!

Anyway, to your questions about the motors, I took the outer case off one
of the motors, the aperture I presume, but could not get the other one
off without risking breaking screws and things - I'll let someone else
take that responsibility! After that the aperture cooled down by 30C or so,
the fiilter was still running quite hot. But both of them worked
perfectly throughout the data run on Wed. night, none of the usual problems
occurred.

Now they are going to move the irps upstairs to it's designated spot,
as someone else wants to use the space where it has been. I'll try to make 
sure they keep everything together - there is great potential for things
getting lost out there at the moment.

See you soon,
Rodney