From julvesta@cv3.cv.nrao.edu Tue Jul 2 13:47:38 2002 Date: Tue, 2 Jul 2002 13:47:34 -0600 (MDT) From: Jim Ulvestad X-X-Sender: julvesta@coyote To: Peggy Perley Subject: BV044 (fwd) MIME-Version: 1.0 X-Lines: 30 Status: RO Content-Type: TEXT/PLAIN; charset="US-ASCII" Content-Length: 1058 See paragraph 2. Does this sound like something that Tom Briscoe might do? Will forward the original message to you too. j ---------- Forwarded message ---------- Date: Tue, 2 Jul 2002 15:02:59 -0400 From: Jay Lockman To: schedsoc@zia.aoc.NRAO.EDU Cc: julvesta@procrustes.gb.nrao.edu, bclark@procrustes.gb.nrao.edu, kkellerm@procrustes.gb.nrao.edu, fowen@procrustes.gb.nrao.edu, ppalmer@procrustes.gb.nrao.edu, jwrobel@procrustes.gb.nrao.edu Subject: BV044 Jim's suggestion that the project be reobserved sounds resonable enough if it doesn't put a strain on the system. We have to presume that if they resubmitted the proposal it would receive a grade similar to the one it got first time around. But to protect our users from themselves (and possibly from innocent typos), would it be possible to have someone look over every set of correlator instructions with the appropriate proposal in hand to make sure that one does not contradict the other? Jay From julvesta@cv3.cv.nrao.edu Tue Jul 2 13:48:18 2002 Date: Tue, 2 Jul 2002 13:48:13 -0600 (MDT) From: Jim Ulvestad X-X-Sender: julvesta@coyote To: Peggy Perley Subject: Re: BV044 = Polarization of circumstellar H20 masers (fwd) MIME-Version: 1.0 X-Lines: 92 Status: RO Content-Type: TEXT/PLAIN; charset="US-ASCII" Content-Length: 3413 Original question and my suggestion. j ---------- Forwarded message ---------- Date: Tue, 2 Jul 2002 12:42:39 -0600 (MDT) From: Jim Ulvestad To: Scheduling Officer Cc: Jim Ulvestad , Barry Clark , Ken Kellermann , Jay Lockman , Frazer Owen , Pat Palmer Subject: Re: BV044 = Polarization of circumstellar H20 masers I agree that this was the observer's error. But we should be willing to be a little flexible for a highly rated proposal. I'd vote for re-observing. But make sure that he understands it's his mistake, and that he needs to do something different with his key file next time. jim On Tue, 2 Jul 2002, Scheduling Officer wrote: > Committee: While the proposal cover sheet clearly requested three > correlation passes, this dynamic program was correlated only once > based on instructions submitted with the key file. The tapes were > degaussed long ago so recorrelations are not possible. > > We explicitly tell dynamic observers > > * Please ensure that the correlation parameters you submit with your > sched keyin file are correct. Once your program has been observed > and is being prepared for correlation, we will use the correlation > parameters from your sched keyin file. > > so I believe this was the observer's error. > > Still, should we offer to reobserve this program? Reasons to do so > include (1) the referee rating was 1.25 and (2) it is for Vlemmings' > thesis. Opinions? - Joan > > *********************************************************************** > Scheduling Officer, NRAO, Socorro, New Mexico, USA schedsoc@nrao.edu > *********************************************************************** > > ---------- Forwarded message ---------- > Date: Tue, 2 Jul 2002 10:14:18 -0600 (MDT) > From: Data Analysts > To: schedsoc@aspen.aoc.NRAO.EDU > Subject: BV044 correlation > > > ----- Begin Included Message ----- > > >From vlemming@waal.strw.leidenuniv.nl Tue Jul 2 04:19 MDT 2002 > From: Wouter Vlemmings > Subject: BV044 correlation > To: analysts@zia.aoc.NRAO.EDU > Date: Tue, 2 Jul 2002 12:18:20 +0200 (MEST) > Cc: lkogan@cv3.cv.nrao.edu, langevelde@jive.nl (Huib v.Langevelde), > pdiamond@jb.man.ac.uk (Phil Diamond) > In-Reply-To: <200206121758.LAA25440@agave.aoc.NRAO.EDU> from "analysts@aoc.nrao.edu" at Jun 12, 2002 11:58:19 AM > MIME-Version: 1.0 > Content-Transfer-Encoding: 7bit > X-Lines: 28 > Status: RO > > > Hello, > > Today I received a tape with data of the BV044 observations > "Polarization of Circumstellar water masers". For this proposal we > requested 3 correlator runs, one with all 4 polarizations and > intermediate resolution to do the calibration and 2 runs to get the > highest possible spectral resoltution to be able to detect the > circular polarization as described in the proposal and coversheet. > > Now I only received 1 tape which contains the full 24 hour observation > run in the intermediate resolution. I suppose something didn't go as > planned with the high resolution data. (Or maybe those tapes are sent > later ?) Or is there another problem ? > > Thanks, > Wouter > > > > From analysts@aspen.aoc.NRAO.EDU Tue Jul 2 15:34:56 2002 Date: Tue, 2 Jul 2002 15:34:53 -0600 (MDT) From: Data Analysts To: vlemming@strw.leidenuniv.nl Subject: Re: BV044 correlation Cc: lkogan@aspen.aoc.NRAO.EDU, pperley@aspen.aoc.NRAO.EDU, analysts@aspen.aoc.NRAO.EDU X-Sun-Charset: US-ASCII Content-Length: 2388 X-Lines: 63 Status: RO Dear Wouter, It seems that 3 correlator passes were requested in the proposal and on the proposal cover sheet, but not in the .key (observing schedule) file. We require that these requests be mentioned in the "cornotes" section of the .key file as stated in the informational email you received in January: "* Please ensure that the correlation parameters you submit with your sched keyin file are correct. Once your program has been observed and is being prepared for correlation, we will use the correlation parameters from your sched keyin file." So we used the information in the .key file to correlate the project and only correlated one pass. The project has been released and the tapes degaussed. However, all is not lost. The scheduling committee has agreed that this can be observed again. So we have made a new .key file called bv044b. We have also inserted the cornote: "3 PASSES - email observer for specifics". **(If you send us the parameters for the 3 passes now, this will expedite correlation once it has been reobserved.)** If you have any other questions, please let me know. With best wishes, Meri Stanley NRAO Data Analyst > > > Hello, > > Today I received a tape with data of the BV044 observations > "Polarization of Circumstellar water masers". For this proposal we > requested 3 correlator runs, one with all 4 polarizations and > intermediate resolution to do the calibration and 2 runs to get the > highest possible spectral resoltution to be able to detect the > circular polarization as described in the proposal and coversheet. > > Now I only received 1 tape which contains the full 24 hour observation > run in the intermediate resolution. I suppose something didn't go as > planned with the high resolution data. (Or maybe those tapes are sent > later ?) Or is there another problem ? > > Thanks, > Wouter > > > > -- > =========================================================================== > Wouter Vlemmings vlemming@strw.leidenuniv.nl > Sterrewacht Leiden phone: (+31) 71 5275831 > P.O. Box 9513 fax: (+31) 71 5275819 > 2300 RA Leiden > The Netherlands www: http://www.strw.leidenuniv.nl/~vlemming > =========================================================================== > From gtaylor@aoc.nrao.edu Wed Apr 2 10:24 MST 2003 X-Authentication-Warning: pegasus.aoc.nrao.edu: gtaylor owned process doing -bs Date: Wed, 2 Apr 2003 10:24:24 -0700 (MST) From: gtaylor X-X-Sender: gtaylor@pegasus To: Peggy Perley cc: Greg Taylor Subject: BV044C correlation problem (fwd) MIME-Version: 1.0 X-MailScanner: Found to be clean X-MailScanner-SpamCheck: not spam, SpamAssassin (score=0.1, required 7, DEAR_SOMEBODY, SPAM_PHRASE_02_03, USER_AGENT_PINE, X_AUTH_WARNING) X-Lines: 163 Status: RO Content-Type: TEXT/PLAIN; charset="US-ASCII" Content-Length: 7258 Hi Peggy, I'm forwarding this plea for re-observation from Wouter Vlemmings to you, since this is your call, or perhaps something for the scheduling committee to decide. I'm not sure why he sent this to me. Seems like there is an unfortunate trend for observers to produce ever more complicated experiments. Amy was telling me this morning about another observer who lost the first and last hour due to some complicated setup. I don't know what the answer to this general problem is. Ciao, - Greg ---------- Forwarded message ---------- Date: Wed, 2 Apr 2003 11:54:51 -0500 (EST) From: Wouter Vlemmings To: gtaylor@cv3.cv.nrao.edu Cc: Huib Jan van Langevelde , diamond@astro.cornell.edu Subject: BV044C correlation problem Dear Dr. Taylor, After finally being able to check my VLBA data for project BV044C, I found that the data was not correlated as expected. I communicated with the data anaylist (Jason Wurning) and it seems that a miscommunication regarding the use of the IF term led to only half of the data being correlated. (The email correspondence is attached below). Due to high spectral resolution, many baseband channels and full polarization, the project required multiple (3) correlation passes. Originally, due to my fault, the key file did not include a mention of these multiple passes and the data was reobserved. CoI Phil Diamond wrote the following piece to be included for the correlation notes. > Pass 1: All IFs, all 4 Stokes parameters, 128 spectral channels per > IF, averaging time 7 seconds > > Pass 2: IFs 1 & 2, parallel hands (i.e. RR and LL), 512 spectral channels > for each IF, averaging time 7 seconds. > > Pass 3: IFs 3 & 4, parallel hands (i.e. RR and LL), 512 spectral channels > for each IF, averaging time 7 seconds. Unfortunately, due to the use of the term IF, a mix up occurred. The data consisted of 4 frequency bands, each dual polarization, which were here and in the proposal labelled IFs. Due to the correlator capabilities, at high resolution, only 2 of the frequency ranges could be correlated at the same time. But because of the mixup, at the correlator stage the passes we labelled 2 & 3 were combined resulting in only 2 of the frequency ranges being correlated. As the observations consist maser spectral line data, half of the velocity coverage is missing which severaly compromises the science we intended to perform with the data. I apologize for my part in this mix-up, but unfortunately I see no other solution than to ask to reobserve the project again while we unambiguouly make clear how the correlator process should proceed. best regard, Wouter Vlemmings ----------------- >Date: Tue, 1 Apr 2003 10:25:21 -0700 (MST) >From: Jason Wurnig >To: wouter@astro.cornell.edu >Cc: analysts@agave.aoc.nrao.edu, jwurnig@agave.aoc.nrao.edu >Subject: BV044C correlation information > >Hi Wouter, > >This is in regards to the correlation of BV044C which observed last >August 2002. I think there may be possible misunderstanding on the >language used to specify correlation parameters for the VLBA. > >> I now checked and it seems that I only got 2 correlations on tape. >> 1 correlation with the low resolution and all 4 Stokes and IF's >> and one of the correlation runs with the high resolution for only >> 2 of the 4 IF's. >> Can it be that part of the data was not put on tape, or >> did for some reason the 3rd correlation pass never occur. >> cause this would mean only half of the spectrum is available >> for science which for some sources likely means that >> the most important part is missing. > >There are indeed only two correlation passes for BV044C. The first pass >was with all eight IF channels at 128 spectral channels per IF channel. >The second corre lation pass is the first four IF channels at 512 >spectral channels per IF channel. > >Here are your notes about the correlation of BV044C: > >> Pass 1: All IFs, all 4 Stokes parameters, 128 spectral channels per >> IF, averaging time 7 seconds >> >> Pass 2: IFs 1 & 2, parallel hands (i.e. RR and LL), 512 spectral >channels >> for each IF, averaging time 7 seconds. >> >> Pass 3: IFs 3 & 4, parallel hands (i.e. RR and LL), 512 spectral >channels >> for each IF, averaging time 7 seconds. > > >The correlator can handle up to four IF channels without polarization >cross-hand s. So, we combined your requested pass 2 and pass 3 into a >single pass which is a much more efficient way to correlate. Therefore, >what was correlated was what you had requested, and you should have the >complete data set. > >Now, your Email implies that you did not get all of the data that you had >expect ed. I will interpret this as meaning what you actually wanted was >all eight IFs correlated at 512 spectral channels per IF channel. If that >is the case, then certainly the upper four IF channels were not >correlated since they were not req uested. > >So, I believe the underlying problem arose from the misinterpretation of >the rat her vague and loose term 'IF'. In the informal language of the >VLBA, the data of an 'IF' refers to all of the spectral point measurements >at a given frequency, bandwith, and polarization (i.e. an IF is one >channel at one polarization, not both polarizati ons). So experiment >BV044C had a total of eight separate IF channels of which you requ ested >IF 1, 2, 3, and 4 which correspond to two complete polarization pairs. > >Other radio arrays use slighty different jargon to describe 'IF's, but >keep in m ind that the VLBA is flexible enough that it can observe up to >eight channels of a s ingle polarization (i.e. eight channels of LCP only) >which is one reason why the termi nology for an 'IF' evolved as such. It >is also worth mentioning that the VLBA h as four physical IF distributors >labeled A, B, C, and D (not 1, 2, 3, 4). In project BV 044C, only two IF >distributors (B and D) were used, so making reference to more that t wo >physical 'IFs' is bogus. So, summing up this explanation of terminology >to get at the crux of the matter: It takes two 'IF' channels of data (one >RCP and one LCP ) to create one complete polarization pair, and it takes >eight 'IF' channels to get f our complete polarization pairs of data. > >If your science is compromised because of this possible error, then you >can alwa ys propose to reobserve again. However, if you reobserve, you >absolutely must incl ude clear, complete, and correct correlation >instructions within the .key file befor e your project observes. Keep in >mind that the people correlating your project do not see the original >observing proposal and are entirely dependent upon what instruction you >provide in your schedule. > >Regards, >Jason Wurnig ------------- -- ==================================================================== Wouter Vlemmings wouter@astro.cornell.edu 524 Space Sciences Building phone: 1-607-255-0612 Cornell University fax: 1-607-255-3433 Ithaca, NY 14853-6801 U.S.A. www: http://www.strw.leidenuniv.nl/~vlemming ====================================================================