Search found 29 matches

by smyers
Tue Jan 27, 2015 1:21 pm
Forum: VLA Sky Survey
Topic: Call for Open Community Comment on the VLASS Proposal
Replies: 5
Views: 2826

Call for Open Community Comment on the VLASS Proposal

The NRAO announces an open call for community public comment on the VLA Sky Survey (VLASS) proposal, prior to the VLASS Community Review that will take place March 4-6, 2015. The Survey Science Group (SSG) and Science Working Groups have finalized the proposal for the VLA Sky Survey (VLASS) proposal...
by smyers
Mon Sep 08, 2014 12:30 pm
Forum: VLA Sky Survey
Topic: First Draft of VLASS Proposal Now Available
Replies: 1
Views: 1250

First Draft of VLASS Proposal Now Available

All, The first draft of the VLASS survey proposal is now posted on the NRAO VLASS wiki at https://safe.nrao.edu/wiki/pub/JVLA/VLASS/VLASS.v11.pdf This draft underwent some internal review and comment, and revision is currently underway based on those comments. We expect a new draft will be completed...
by smyers
Fri Jun 13, 2014 5:19 pm
Forum: VLA Sky Survey
Topic: VLASS Preliminary Science Definition available
Replies: 0
Views: 2587

VLASS Preliminary Science Definition available

All, the VLASS SSG has posted a Preliminary Summary of the VLA Sky Survey giving a rough initial definition of the survey. You can find this linked from the VLASS Home Page at: https://science.nrao.edu/science/surveys/vlass/vlass#vlass-preliminary-definition-and-summary-available The current working...
by smyers
Tue Apr 08, 2014 11:20 am
Forum: Galactic Working Group
Topic: VLASS Calculator
Replies: 20
Views: 4769

Re: VLASS Calculator

Regarding the frequency dependence, it sounds to me like the effective time on sky scales as the beam size. For a large survey with tight packing of scans, any point on sky will be surveyed by every part of the primary beam. If we assume a reference point at band center, all other parts of the band...
by smyers
Tue Apr 08, 2014 11:15 am
Forum: Galactic Working Group
Topic: VLASS Calculator
Replies: 20
Views: 4769

Re: VLASS Calculator

So you think the limit you mentioned above ("we found issues when we switched phase centers faster than 1 sec") doesn't apply if there are shorter integrations? I knew that shorter integrations were possible but was applying a 1 sec limit on switching the phase center based on that statem...
by smyers
Mon Apr 07, 2014 7:00 pm
Forum: Galactic Working Group
Topic: VLASS Calculator
Replies: 20
Views: 4769

Re: VLASS Calculator

You don't need to keep the rate at 0.2*fwhm in 1 sec, as you can set the integration time less than that. for sband we used 0.5sec integrations and changed phase centers every 4sec. But the data rates become prohibitive the shorter you go especially in 3-bit mode over Ku-band 6GHz wide (with 2MHz ch...
by smyers
Mon Apr 07, 2014 4:18 pm
Forum: Communication / Education / Outreach Working Group
Topic: Twitter outreach
Replies: 8
Views: 2943

Re: Twitter outreach

sounds good, #VLASS it is!

when and what should we start tweeting and from where?

-s
by smyers
Mon Apr 07, 2014 12:18 pm
Forum: Galactic Working Group
Topic: VLASS Calculator
Replies: 20
Views: 4769

Re: VLASS Calculator

First, as per a separate email discussion we had: We actually hold the phase center constant for several integrations (we found issues when we switched phase centers faster than 1 sec). So you are not smearing across the synth beam, that would be very bad! Thats why I mentioned that faster scanning ...
by smyers
Fri Apr 04, 2014 12:57 pm
Forum: Technical Working Group
Topic: Technical Issue: Is OTF polarimetry possible?
Replies: 2
Views: 1322

Re: Technical Issue: Is OTF polarimetry possible?

OTF polarimetry is no different (or only slightly different) than interferometry with classic stepped mosaics. I guess we will know the answer since we took our S-band Stripe82 survey in full polarization. Preshanth and Russ Taylor also have some C-band observations in stepped mode that look pretty ...
by smyers
Fri Apr 04, 2014 12:48 pm
Forum: Galactic Working Group
Topic: VLASS Calculator
Replies: 20
Views: 4769

Re: VLASS Calculator

Rick, Again, there is no issue with spacings. The field spacing does not enter into the calculation at all. The calculation is done in the "continuous scanning" limit. Please see https://science.nrao.edu/facilities/vla/docs/manuals/obsguide/modes/mosaicking for details on the calculation. ...

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