From: <Simon.Ellingsen_at_email.protected>
Date: Thu, 23 Aug 2012 14:41:58 +1000

Dear LBAers,

A month or so ago Brett and Warren spent several weeks in Ceduna working on the L-Band
system and the Ceduna maser. Brett was able to find a fault in the maser electronics
(he can provide more details for anyone who is interested), which appears to have been
the cause of the long standing poor phase performance of Ceduna. Jamie and Cormac
have undertaken a couple of Hobart-Ceduna test observations - one while the
maser was tuning and another more recently. These experiments show considerably
better phase stability on the one baseline than we have observed in recent years.

The real test of course will come during the next few LBA observing sessions, however,
we are hopeful that the source of this problem may finally have been identified
and corrected.

Begin forwarded message:

>From: Cormac Reynolds <c.reynolds_at_curtin.<!--nospam-->edu.au>
>Subject: Re: More Ceduna-Hobart test data
>Date: 22 August 2012 3:56:52 PM AEST
>To: Jamie McCallum <Jamie.McCallum_at_utas.<!--nospam-->edu.au>
>Cc: Simon Ellingsen <Simon.Ellingsen_at_utas.<!--nospam-->edu.au>, Jim Lovell <Jim.Lovell_at_utas.<!--nospam-->edu.au>, Brett Reid <Brett.Reid_at_utas.<!--nospam-->edu.au>, jayb <jayb_at_postoffice.<!--nospam-->utas.edu.au>, Hayley <H.Bignall_at_curtin.<!--nospam-->edu.au>
>
>hi Jamie,
>
>the correlation/pipelining of the Ceduna test data set is complete.
>The pipeline results are available from:
>
>http://cira.ivec.org/dokuwiki/doku.php/correlator/records/t12220
>
>The data quality looks good throughout the run (the gap in the
>pipeline is due to Hobart wind stow). The phase stability is not
>significantly better than the previous test, but we may well be being
>dominated by the atmosphere at this stage. We'd have to have a 3rd
>antenna in the array to say any more on that. In any case, this phase
>stability is good enough for normal phase referencing at this
>frequency.
>
>The raw and pipeline calibrated FITS files are available from:
>
>ftp://cira.ivec.org/t12220/T12220.FITS
>ftp://cira.ivec.org/t12220/T12220.CAL.FITS
>
>in case you want to play with the data some more.
>
>cheers,
>Cormac.
>
>On 20 August 2012 08:19, Jamie McCallum <Jamie.McCallum_at_utas.<!--nospam-->edu.au> wrote:
>>Hi Cormac,
>>I've transferred the second lot of the Ceduna-Hobart test data onto
>>the pbstore, along with the vex file. The experiment code is t12220 and it's
>>~6 hours of 0537-441, at 6.6 GHz. I've had a quick look at the data with a
>>test correlation and it looks very hopeful. Please let us know what you
>>find.
>>Cheers,
>>Jamie
>>
>>PS -
>>Some notes on the data:
>>Hobart clock offset = 10.8 us
>>Ceduna clock offset = 9.56 us.
>>Hobart was windstowed between 0109 and 0240.
>>
>
>
>
>--
>----------------------------------------------------
>Cormac Reynolds
>Phone: +61 8 9266 3785
>Fax: +61 8 9266 9246
>email: c.reynolds_at_curtin.<!--nospam-->edu.au
>----------------------------------------------------

Regards

Simon

--
Simon Ellingsen : Associate Professor Physics & Astronomy, University of Tasmania
email : Simon.Ellingsen_at_utas.<!--nospam-->edu.au
WWW   : http://fcms.its.utas.edu.au/scieng/physics/pagedetails.asp?lpersonId=681
Phone : 6226 7588 ;                       Area Code : +61 3 (International)
               6226 2410 (Fax)                03 (Australia)

Received on 2012-08-23 14:43:07