Facilities > VLA > Documentation > Manuals > VLA Observational Status Summary 2014A > Proposing for the VLA for the current semester

Proposing for the VLA for the current semester

by stephanw — last modified Aug 04, 2015 by Lorant Sjouwerman

The 2014A Call for Proposals

The 2014A Call for Proposals details the general capabilities being offered for the Karl G. Jansky Very Large Array (VLA).

In addition to these general capabilities, NRAO continues to offer shared risk observing options for those who would like to push the capabilities of the VLA beyond those offered for general use.  These are the "Shared Risk Observing" (SRO) and "Resident Shared Risk Observing" (RSRO) programs.

Details about what is being offered for each program along with a list of the steps that should be completed for each proposal category is given below.  In addition, a summary of the links to updated documentation and tools to prepare your proposal is also given below (including an updated VLA Observational Status Summary (OSS), and the Guide to Observing with the VLA).

If you have any questions or problems with any link or tool, please submit a ticket through the NRAO Helpdesk.

 

General and Shared-Risk Observing

Summary of Capabilities

As described in the 2014A Call for Proposals, the VLA offers continuous frequency coverage from 1-50 GHz in the following observing bands: 1-2 GHz (L-band); 2-4 GHz (S-band); 4-8 GHz (C); 8-12 GHz (X); 12-18 GHz (Ku); 18-26.5 GHz (K); 26.5-40 GHz (Ka); and 40-50 GHz (Q).  Both single pointing and mosaics with discrete, multiple, field centers will be supported.  Data rates of up to 60 MB/s (216 GH/hour) will be available to all users, combined with correlator integration time limits per band and per configuration, as described in the VLA OSS.  Data rates in excess of 25 MB/s require additional justification. There are also some limitations on frequency settings and tuning ranges, please consult the VLA OSS for further details

The GENERAL capabilities being offered are:

Capability Description
8-bit samplers
  • Standard default set-ups for:
    • 2 GHz bandwidth continuum observations at S/C/X/Ku/K/Ka/Q bands (16 x 128 MHz sub-bands)
    • 1 GHz bandwidth continuum observations  at L-band (16 x 64 MHz sub-bands)
  • Flexible set-ups for spectroscopy, using two independently tunable 1 GHz basebands, each of which can be split into up to 16 flexibly tunable sub-bands
  • Single, dual & full polarization products
  • Up to 16,384 channels (summed over all polarization products)
3-bit samplers
  • Standard default set-ups for:
    • 8 GHz bandwidth continuum observations at K/Ka/Q bands
    • 6 GHz bandwidth at Ku band
    • 4 GHz bandwidth at C/X bands
  • Flexible set-ups for spectroscopy, using four independently tunable 2 GHz basebands, each of which can be split into up to 16 flexibly tunable sub-bands
  • Single, dual & full polarization products
  • Up to 16,384 channels (summed over all polarization products)

Sub-arrays

  • Up to 3 independent sub-arrays using standard 8-bit continuum set-ups
Phased-array for VLBI
  • VLA Phased Array ("Y27") for VLBI (see the VLBA call for proposals and the VLBA Observational Status Summary for a detailed description of the VLA Phased Array capabilities being offered)

 

Shared Risk Capabilities can be set up via the Observing Preparation Tool (OPT) and run through the dynamic scheduler (without intervention) but they are not as well tested as General capabilities.  A summary of the SHARED RISK Capabilities being offered are:

  • Correlator dump times as short as 50 ms;
  • Use of the new low frequency P-band receivers (230-470 MHz) for Stokes I continuum imaging;
  • Mixed 3-bit and 8-bit sampler set-ups.

We expect that most Shared Risk programs will have none or only minor problems that can be corrected quickly.  However, if a Shared Risk program fails and it becomes clear that detailed testing with PI expertise is needed, then the PI team must send an experienced member from their team to help troubleshoot the problem.  If adequate support from the PI team is not given, then the team will be deemed to have forfeited their time on the telescope.  The estimated duration of the time at NRAO is to be determined based on discussions with the NRAO staff and management and the PI team.  However, the length of time required at NRAO, Socorro is expected to be on the order of a few weeks and should not exceed 1 month.

 

Steps to Completion

  1. Read the NRAO 2014A Call for proposals description for summaries of the capabilities being offered for General and Shared-Risk Observing.
  2. If you are proposing for spectral line observations, run the General Observing Setup Tool (GOST, a java application) to define your correlator set-up and save a snapshot of the tool GUI to disk.  Note:
  3. Write a scientific justification for your proposal.  Use the VLA Exposure Calculator to understand what sensitivity you will get for a given frequency, bandwidth, and integration time.  Note that the technical information should be included in the Technical Justification section and does not need to be included with the scientific justification.  Save your scientific justification as a PDF file.
  4. Log into the NRAO Interactive Services page (my.nrao.edu) and click on the "Proposals" tab in the top left to create and submit a new proposal for the VLA.  Once you are in the tool, extensive help is available in the tool by clicking on the "Help" button in the top right of the tool interface (see also the links to the help documentation below).  In the PST:
    • Fill in the relevant fields for each section of your proposal;
      • If you are proposing for continuum observations, select Observing Type = "Continuum" in the General section of your proposal.   Then add a Continuum Resource, selecting the appropriate band you want to observe in.   Default optimum continuum setups for each band are defined in the PST.
      • If you are proposing for spectral line observations, Select Observing Type = "Spectroscopy" in the General section of your proposal.  Then add a Spectroscopic Resource and attach the GOST snapshot (that you saved previously) to this resource.  The GOST snapshot describes everything needed to specify the lines you want to observe and what correlator resources are needed for the observation.
    • Upload your scientific justification as a PDF file;
    • Technical justifications are now included as a separate section in the proposal.  Click on the Technical Justification page in the proposal and fill in the appropriate boxes.
    • Note that the PST allows observers to specify multiple resource types (e.g., you can have one proposal that specifies general and/or RSRO correlator resources).  If any resource is RSRO, it will be a RSRO proposal.
  5. When your proposal is complete, validate it to make sure there are no obvious omissions or mistakes.
  6. When you are satisfied, submit your proposal in the PST.

 

Resident Shared Risk Observing (RSRO)

Summary of Capabilities

The Resident Shared Risk Observing (RSRO) program provides access to extended capabilities of the VLA that require additional testing in exchange for a period of residence to help commission those capabilities. Capabilities that would fall under the RSRO program include, e.g.,

  • Correlator dump times shorter than 50 ms;
  • Data rates above 60 MB/s;
  • Use of recirculation in the correlator;
  • More than 3 sub-arrays with the 8-bit samplers;
  • Sub-arrays with the 3-bit samplers or mixed 3/8-bit samplers;
  • On-the-fly (OTF) interferometric mosaicing;
  • Complex phased array observations (e.g., pulsar and complex VLBI observing modes);
  • Use of the new low frequency receivers with the 4-band feeds (58-84 MHz)

 

Steps to Completion

  1. Read the 2014A NRAO Call for Proposals for a summary of the capabilities being offered for General and Shared-Risk Observing.
  2. If you want more than what is offered for General or Shared-Risk Observing then you likely want a Resident Shared Risk capability (one that is not well-tested or may even need additional development).  If you propose for a RSRO capability, you (or an experienced person on your team) must be able to participate in the RSRO program by coming to Socorro to help with the development and testing process.
  3. Write a scientific justification for your proposal.  Use the VLA Exposure Calculator to understand what sensitivity you will get for a given frequency, bandwidth, and integration time.  Describe what you want to do with the correlator and why this is in the RSRO Category in the Technical Justification section.  Contact NRAO staff if you have questions about exactly what is feasible.
  4. Log into the NRAO Interactive Services page (my.nrao.edu) and click on the "Proposals" tab in the top left to create and submit a new proposal for the VLA.  Once you are in the tool, extensive help is available in the tool by clicking on the "Help" button in the top right of the tool interface (see also the links to the help documentation below).  In the PST:
    • Fill in the relevant fields for each section of your proposal;
    • Even as a RSRO proposal, you will need to create a 'Resource' in the PST and select the "WIDAR RSRO" Back End.  This will give you a text field in which you can type a description of your set-up.  This is in addition to the justification of that set-up in the main justification PDF file;
    • Upload your scientific justification as a PDF file;
    • Technical justifications are now included as a separate section in the proposal.  Click on the Technical Justification page in the proposal and fill in the appropriate boxes. The last box at the bottom of the Technical Justification page should be used to describe your RSRO effort.  Identify who in your team can come to Socorro to help make this capability possible and how their background and expertise can be applied to this development.  Working with NRAO staff, estimate the level of effort that is likely to be needed for this development and specify how long a member of your team can come to NRAO.  Mention any support request for accommodation expenses in your RSRO justification.
    • Note that the PST allows observers to specify multiple resource types (e.g., you can have one proposal that specifies general, shared-risk and RSRO correlator resources).  If any resource is RSRO, it will be a RSRO proposal.
  5. When your proposal is complete, validate it to make sure there are no obvious omissions or mistakes.
  6. When you are satisfied, submit your proposal in the PST.

Considerations

A Resident Shared Risk Observing proposal should contain:

  1. A scientific justification, to be peer reviewed as part of NRAO's current time allocation process, submitted through the Proposal Submission Tool.  Note that RSRO correlator resources should be specified as plain text on the Resources page in the PST by selecting "WIDAR RSRO" as the backend.
  2. The technical justification should identify the personnel who will be involved in the residency and describe how their expertise will be used to address the critical priorities of VLA development relating to their proposal.  The proposed dates of the residency must be included, so that the residency can be matched to VLA development planning.  This section will be reviewed by NRAO staff.  It is expected that NRAO will be able to provide accommodation in the NRAO Guest House, subject to availability.  Other support may be available separately through the NRAO Visitor's Program.  Proposals that do not require Observatory support will have a substantial advantage over those that request NRAO resources.  Specify any support required in the Technical Justification section.

The acceptance of a RSRO proposal will depend on the outcome of the time allocation process, and proposals will also be evaluated by NRAO staff in terms of the priorities and benefits to the VLA development and commissioning activities.

One month of resident commissioning effort is required for every 20 hours of VLA time awarded to a RSRO project.  Unlike previous years, there is no minimum requirement for the amount of residency at NRAO however, the amount of time spent at NRAO to help develop the program should be realistically matched to the expected effort.  The time proposed at NRAO should be discussed with NRAO staff to determine what is reasonable.  The length of time a RSRO expert should be needed at NRAO is expected to be on the order of a few months.

The period(s) of residency may occur in advance of the observing time awarded in order to decouple essential scientific requirements (such as array configuration) from other factors which may affect when personnel are available (such as teaching schedules).  However, observers should be present for one week prior to their observations in order to become familiar with the latest developments and to set up their observations.  In the special case of Target of Opportunity proposals a VLA staff collaborator may be required for setting up observations on short timescales.

It should be noted that having a member of the NRAO-VLA staff as a collaborator on a RSRO proposal will not satisfy the residency requirement.  Graduate students may satisfy the residency requirement, provided relevant expertise is demonstrated in section (b) of the proposal.  Graduate students should be accompanied by their adviser at the start of their residency.  Resident personnel will work under NRAO management in order to optimize the overall effort.  A set of clear goals will be agreed upon in advance of the start of the residency.

The types of proposals considered under the RSRO program may include both large (>200 hours) and small (~10-200 hours) projects.  Qualified large projects proposed by consortia will be considered as long as the residency requirements are met.  A single individual may satisfy the residency requirement for several small projects.

Resident observers will also be permitted to take part in the "exploratory proposal" section of the NRAO VLA Development - Staff Observing program, in addition to the time allocated by the process described above. Thus, once a person has obtained RSRO time, they may also apply for "exploratory time" through the Director's Discretionary Time allocation process by writing a proposal request to the Assistant Director for NM Operations.

RSRO participation without a science proposal:

In some cases, an individual may want to participate in development activities without writing a science proposal.  A participant may arrange to visit Socorro to contribute to development activities by submitting a proposal directly to the Assistant Director for NM Operations (nraonmad@nrao.edu) containing a proposal for who will come and the budget support requested (see item (b) of the RSRO Proposal requirements described above).  If the Director approves of the request then the individual may come to Socorro to contribute to development activities.  The participant may then obtain observing time either by submitting a proposal at a regular proposal deadline, or through the "exploratory proposal" section of the NRAO VLA Development - Staff Observing program while in residence (see below).  Such visits should conform to the residency requirements above.  Proposals to visit Socorro under this program may be submitted at any time.

 

NRAO Staff Observing program

The scientific staff of NRAO-NM have had an immense stake in the continuing enhancement of the VLA.  Observatory staff are also in the best position to test and validate enhanced or emerging capabilities of the VLA.  In order to optimize the extent to which the staff can push the instrument and certify its data products, no instrumental constraints (e.g., upon correlator capabilities) will be placed on the observing resources available to staff observers, and up to 500 hours per year will be reserved for peer-reviewed staff access to the VLA under the shared risk observing program.  Assignment of telescope time under this program will also be on a shared-risk basis in the sense that no implied commitments to complete each observing program will be made.  NRAO VLA staff who are allocated observing time under this program will also be free to collaborate on Shared Risk and RSRO projects.   However, NRAO VLA staff will not satisfy the residency requirement on RSRO proposals as stated above.

Exploratory proposals for small projects (<10 hours of VLA time) by NRAO VLA staff, or residents working on VLA development, will also be considered under this program.  Such proposals will be reviewed quickly via a process similar to that currently used for exploratory proposals.

 


Documentation Summary

https://science.nrao.edu/enews/6.7 - The August 1, 2013 NRAO call for proposals.

https://science.nrao.edu/facilities/vla/docs/manuals/oss2014a -- The updated VLA Observational Status Summary (OSS) for 2014A semester providing a reference for those contemplating use of the VLA for their astronomical research.  This document summarizes the instrumental status of the Karl G. Jansky Very Large Array (VLA) and should be used for the August 1, 2013 proposal deadline.

NRAO User Portal is a gateway to the NRAO interactive services that include the Proposal Submission Tool (PST).  Click on the "Proposals" tab in the top left to create and submit a new proposal for NRAO telescopes.  You can also see the status of your previously submitted proposals.

  • The NRAO Proposal Submission Tool Guide is available on-line [html] and in pdf format [pdf].
  • The PST has been used for GBT observing proposals since June 2005, VLA observing proposals since January 2006, and VLBA/HSA observing proposals since June 2008.

The VLA Exposure Calculator is available to help you understand what sensitivity you will get for a given frequency, bandwidth, and integration time.  The results from the Sensitivity Calculator should be used in your proposal technical justification.

GOST -- The General Observing Setup Tool (GOST) must be run for all spectral line General & Shared-Risk Observing proposals (not for Resident Shared Risk proposals).  Download the java GUI, start the tool GUI interface, select what band you want, list the lines you will be observing , and then click the "save" button at the bottom to create a snapshot that will be saved to a PDF file on disk.  This file should then be uploaded into the Proposal Submission Tool to define the correlator resources you are asking for.

https://science.nrao.edu/facilities/vla/docs/manuals/obsguide -- VLA Observing Guide


To report errors or problems encountered in any link or while using any NRAO tool listed here, please submit a ticket through the NRAO Helpdesk.

For historical purposes we provide a list of links to earlier observing modes since WIDAR came online in March, 2010.

Many thanks to all the VLA staff and our RSRO participants who have worked long and hard to commission these capabilities and who have helped to create this extensively updated set of documentation.