From: <Philip.Edwards_at_email.protected>
Date: Mon, 27 Apr 2009 11:39:38 +1000

Hi Chris,

Obvious place to check first is the observing logs on the wiki, but frustratingly these do not exist for ATCA and Mopra for this run!!
We need to do better than that...

V271b is an x-band run from last November.
Inspection of caobs logs reveals these are not LO issues.

>>>ATCA: No detections from No0016 to No0039: some of these scans
>>>are recognized by fourfit as valid (expecially for the
>>>baseline
>>>to Hobart), but they are garbage: the power spectrum is
>>>garbage.

From the v271b.sum file, these scan numbers correspond to times:
Status: O

16 333 09:44:24

39 333 10:52:24

>>>No detection from No0340 to No0345 ( some scans are recognised
>>>valid by fourfit, but, as for above are garbage).
>>>Visibility phases vs time unstable: one of the LOs break the
>>>lock (when the effect is visible, it is present in all BBCs)
>>>and relock at a different phase. Without phase cal data I
>>>cannot check further this theory (see plot in attachment).
>>>Early scan stops : ~4 AP

And for these:

340 334 03:54:44

345 334 04:09:14

The caobs_activity log reports for this experiment:

2008/11/28 08:52:52 open 2008-11-28_0852.V271B
2008/11/28 10:54:32 gap of 4270 s
2008/11/28 21:27:40 close 2008-11-28_0852.V271B
2008/11/28 21:27:43 open 2008-11-28_2127.V271B
2008/11/29 03:08:31 close 2008-11-28_2127.V271B
2008/11/29 03:09:21 open 2008-11-29_0309.V271B
2008/11/29 03:10:32 gap of 192 s
2008/11/29 04:08:52 gap of 840 s
2008/11/29 09:03:05 close 2008-11-29_0309.V271B

So there were clearly gaps (which presumably means telescope idle) at the times in question, hence no fringes.

Looking further, the caobs_error log reports

C 28-NOV-2008 09:43:23 stop
C 28-NOV-2008 09:43:24 stow
I 28-NOV-2008 09:43:24 All active antennas stowing
C 28-NOV-2008 09:44:08 stow
I 28-NOV-2008 09:44:08 All active antennas stowing
C 28-NOV-2008 10:54:25 start

Well, no surprises at no fringes if everything was stowed.
The question then is why was it stowed??

For the second block:

I 29-NOV-2008 03:54:54 All active antennas stowing
E 29-NOV-2008 03:54:54 WIND ALARM - antennas stowing
I 29-NOV-2008 03:55:03 All active antennas stowing
E 29-NOV-2008 03:55:03 WIND ALARM - antennas stowing
C 29-NOV-2008 04:07:53 start

A wind stow.

These need to be logged at the time to save the correlator staff from wasting their time chasing these up.

Cheers,
Phil
Received on 2009-04-27 11:39:38