<div dir="ltr"><div><div>Hi Mark,<br><br></div>Many thanks for that very useful information.<br></div><div>I will double-check the $CLOCK values I was<br></div><div>using.<br><br></div><div>Cheers,<br></div><div>Sam<br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, May 17, 2017 at 5:02 PM, Mark Kettenis <span dir="ltr"><<a href="mailto:kettenis@jive.eu" target="_blank">kettenis@jive.eu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">> From: Hagatiana Andrianomena <<a href="mailto:handrianomena@ska.ac.za">handrianomena@ska.ac.za</a>><br>
> Date: Mon, 15 May 2017 08:51:59 +0200<br>
<br>
Sam,<br>
<br>
Note that if you are using $CLOCK parameters from a correlation with<br>
SFXC, the rates may not be specified in a form that DiFX expects. If<br>
the "unit" isn't specified, SFXC will interpret the rate as usec/sec,<br>
whereas DiFX will interpret the rate as sec/sec.<br>
<br>
Cheers,<br>
<br>
Mark<br>
<div><div class="h5"><br>
> Hi Cormac,<br>
><br>
> Please see attached the vex. I am interested in EF-YS-NK-HH-O8.<br>
><br>
> cheers,<br>
> Sam<br>
><br>
> On Mon, May 15, 2017 at 7:45 AM, Cormac Reynolds <cormac.reynolds@csiro.au><br>
> wrote:<br>
><br>
> > hi Sam,<br>
> ><br>
> > just following up on Adam's point. The most common cause of a very high<br>
> > residual fringe rate (as yours appears to be) in an otherwise functioning<br>
> > array is an error in the station position(s). If you send the vex file you<br>
> > used, and the stations you are interested in, it should be straightforward<br>
> > to say if that is a likely cause or not.<br>
> ><br>
> > cheers,<br>
> > Cormac.<br>
> ><br>
> > On 13/05/17 19:57, Hagatiana Andrianomena wrote:<br>
> ><br>
> >> Hi Adam,<br>
> >><br>
> >> Many thanks for your explanations.<br>
> >><br>
> >> Cheers,<br>
> >> Sam<br>
> >><br>
> >> On Sat, May 13, 2017 at 1:37 PM, Adam Deller <<a href="mailto:adeller@astro.swin.edu.au">adeller@astro.swin.edu.au</a><br>
> >> <mailto:<a href="mailto:adeller@astro.swin.edu.au">adeller@astro.swin.<wbr>edu.au</a>>> wrote:<br>
> >><br>
> >> Hi Sam,<br>
> >><br>
> >> Integration time will affect the maximum fringe rate you are<br>
> >> sensitive to. Shorter integrations = higher fringe rate before you<br>
> >> lose signal due to decorrelation. But normally this is not a<br>
> >> limitation. I would be fairly surprised if a 1 second integration<br>
> >> time was a problem (unless there is an issue with the observing<br>
> >> setup).<br>
> >><br>
> >> Spectral resolution will affect the maximum residual delay you are<br>
> >> sensitive too. Finer spectral resolution = larger delay before you<br>
> >> lose signal due to decorrelation.<br>
> >><br>
> >> These are not DiFX-specific things, but general to radio<br>
> >> interferometers / correlators. To know what values are reasonable,<br>
> >> you need to know your instrument and what the expected residual<br>
> >> fringe rate and delay are.<br>
> >><br>
> >> Cheers,<br>
> >> Adam<br>
> >><br>
> >> On 12 May 2017 at 23:59, Hagatiana Andrianomena<br>
> >> <<a href="mailto:handrianomena@ska.ac.za">handrianomena@ska.ac.za</a> <mailto:<a href="mailto:handrianomena@ska.ac.za">handrianomena@ska.ac.<wbr>za</a>>> wrote:<br>
> >><br>
> >> Hi DiFX users,<br>
> >><br>
> >> I got a question regarding the integration time in the setup:<br>
> >> SETUP default<br>
> >> {<br>
> >> tInt = 1.000000<br>
> >> fftSpecRes = 0.12500000<br>
> >> specRes = 0.12500000<br>
> >> doPolar = True<br>
> >> maxNSBetweenACAvg = 2000000<br>
> >> }<br>
> >><br>
> >> I got this default setup by running oms2v2d using the .oms file<br>
> >> from the experiment. When running the difx I got no fringe but<br>
> >> from changing the tInt to<br>
> >> 0.08 and both fftSpecRes and specRes the result seems to suggest<br>
> >> I got fringe (see plot attached).<br>
> >><br>
> >> I am not quite sure whether it is a naive question but I wonder<br>
> >> if there is a simple rule of thumb to get the right values of<br>
> >> those parameters in order to get fringe. I do not have much<br>
> >> experience with DiFX I must say though.<br>
> >><br>
> >> Regards,<br>
> >> Sam<br>
> >><br>
> >> ______________________________<wbr>_________________<br>
> >> Difx-users mailing list<br>
> >> <a href="mailto:Difx-users@listmgr.nrao.edu">Difx-users@listmgr.nrao.edu</a> <mailto:<a href="mailto:Difx-users@listmgr.nrao.edu">Difx-users@listmgr.<wbr>nrao.edu</a>><br>
> >> <a href="https://listmgr.nrao.edu/mailman/listinfo/difx-users" rel="noreferrer" target="_blank">https://listmgr.nrao.edu/<wbr>mailman/listinfo/difx-users</a><br>
> >> <<a href="https://listmgr.nrao.edu/mailman/listinfo/difx-users" rel="noreferrer" target="_blank">https://listmgr.nrao.edu/<wbr>mailman/listinfo/difx-users</a>><br>
> >><br>
> >><br>
> >><br>
> >><br>
> >> --<br>
> >> !=============================<wbr>==============================<wbr>==!<br>
> >> Dr. Adam Deller<br>
> >> ARC Future Fellow, Senior Lecturer<br>
> >> Centre for Astrophysics & Supercomputing<br>
> >> Swinburne University of Technology<br>
> >> John St, Hawthorn VIC 3122 Australia<br>
> >> phone: <a href="tel:%2B61%203%209214%205307" value="+61392145307">+61 3 9214 5307</a> <tel:+61%203%209214%205307><br>
> >> fax: <a href="tel:%2B61%203%209214%208797" value="+61392148797">+61 3 9214 8797</a> <tel:+61%203%209214%208797><br>
> >><br>
> >> office days (usually): Mon-Thu<br>
> >> !=============================<wbr>==============================<wbr>==!<br>
> >><br>
> >><br>
> >><br>
> >><br>
> >> ______________________________<wbr>_________________<br>
> >> Difx-users mailing list<br>
> >> <a href="mailto:Difx-users@listmgr.nrao.edu">Difx-users@listmgr.nrao.edu</a><br>
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> >><br>
> >><br>
> > ______________________________<wbr>_________________<br>
> > Difx-users mailing list<br>
> > <a href="mailto:Difx-users@listmgr.nrao.edu">Difx-users@listmgr.nrao.edu</a><br>
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> ><br>
><br>
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