From: <Roopesh.Ojha_at_email.protected>
Date: Fri, 4 Nov 2005 14:04:58 +1100 (EST)

Hi Brett and Jim

Thanks for the update and your response Jim. Losing dual-pol at Hobart (or
anywhere else) would be a grievous loss for this experiment. However, if
it is a choice between single-pol and no Hobart, single-pol is still
useful for the precious uv-coverage it provides leading to a better I
image. Obviously, the best possible I image is essential for getting a
decent P image.

So please try to get the dual-pol receiver working. If that fails let us
fall back on the single-pol receiver.

Thanks very much to everyone at Hobart for putting in the work.
Cheers
Roopesh

On Fri, 4 Nov 2005, Jim Lovell wrote:
>Hi Brett,
>
>The most important remaining experiment is V187b. It's a polarisation
>experiment and requires the dual pol X-band receiver. My suggestion
>would be to drop everything and concentrate on bringing the X-bad
>receiver on line (weather permitting!) in time for V187b. Roopesh may
>comment on whether single-pol X-band at Hpbart is still useful. The
>intervening experiments are tests, so are less important (the NZ
>fringe check VT03d mostly needs big antennas) but V187b is a well
>ranked proposal and should take priority.
>
>Cheers,
>Jim
>
>--
>Dr Jim Lovell, Jim.Lovell_at_csiro.<!--nospam-->au
>CSIRO Australia Telescope National Facility Ph: (02) 6125 6715
>c/o RSAA, Mt Stromlo Observatory, Fax: (02) 6125 0260
>Cotter Road, Weston ACT 2611 Mobile: 0412 127364
>Australia http://www.atnf.csiro.au/people/Jim.Lovell
>At Tidbinbilla Ph (02) 6201 7842 (RA Lab), x7800 (switch), x7940(shift)
>
>
>
>On 04/11/2005, at 8:07 AM, Brett Reid wrote:
>
>>> Hobart update
>>>
>>> Power was off in the Hanslow Road area in Cambridge near the
>>> Radiotelescope between 4am and 6:15 am.
>>> I noticed tree branches down in lots of places during the drive
>>> over and
>>> the broadcast stations and street lighting had numerous interruptions.
>>> The antenna is still wind stowed.
>>> The diesel ran during the power interuption, powering our cryo
>>> compressor
>>> and S/X receiver. Unfortunately the L band receiver and dual pol X
>>> band
>>> receiver's cryodynes were not connected and have warmed. To recool
>>> either
>>> or both the receivers we need to take the vacuum pump to the focus.
>>> To do
>>> this we need the wind to die down. We need a day to cool the X band
>>> and a
>>> several hours of calmer weather to cool the L band. We have found
>>> previously that we cannot detect sources in single dish mode when
>>> either
>>> of these receivers are warm.
>>>
>>> We feel it is best to observe with the S/X RHC only for v187b if we
>>> are
>>> not able to cool the dual pol X band receiver.
>>> We will try and get the L band as cold as we can once it is safe to
>>> do so.
>>> If any one, such as affected PIs, has some input as to which
>>> receiver to
>>> concentrate on getting cold, given the above constraints and the
>>> remaining experiments, then please let me know.
>>>
>>> Cheers,
>>> Brett and Jamie McCallum.
>>>
>>> Current weather warning follows:
>>>
>>> IDT28100
>>> Australian Government Bureau of Meteorology
>>> Tasmania
>>>
>>> TOP PRIORITY FOR IMMEDIATE BROADCAST
>>> SEVERE WEATHER WARNING
>>> for Damaging Winds
>>> For people throughout Tasmania
>>> Issued at 4:25 am on Friday 4 November 2005
>>>
>>> Synoptic Situation: A low pressure system south of Tasmania is
>>> slowly moving
>>> away.
>>>
>>> West to northwest winds strong enough to bring down some tree branches
>>> and power
>>> lines are expected over Tasmania, particularly southern areas, this
>>> morning.
>>> Conditions are expected to steadily improve during the morning
>>>
>>> The maximum wind gust is expected to be about 110 km/h.
>>>
>>> The State Emergency Service advises that people should secure loose
>>> outside
>>> items.
>>>
>>>
>>> The next warning is due to be issued by 11:00am Friday
>>>
>>> This warning is also available through TV and Radio broadcasts; the
>>> Bureau's
>>> website at www.bom.gov.au or call 1300 659 216. The Bureau and
>>> State Emergency
>>> Service would appreciate this warning being broadcast regularly.
>>>
>>>
>>>
>>>
>>>
>>> Brett Reid
>>> Observatory Manager, Radio Telescopes
>>> University of Tasmania
>>> School of Mathematics and Physics
>>> phone + 61 3 6248 5285
>>> email brett.reid_at_utas.<!--nospam-->edu.au
>>> web http://www-ra.phys.utas.edu.au/~breid/
>
>

***********************************************
Roopesh Ojha
Research Scientist
Australia Telescope National Facility. CSIRO
PO Box 76, Epping, NSW 1710, Australia
61-02-9372-4174 (work), 61-02-9372-4310 (fax)
Homepage: http://www.atnf.CSIRO.AU/~rojha/
***********************************************
Received on 2005-11-04 14:05:22