Proposing for the VLA for the Next Semester
The 2016A Call for Proposals
The 2016A Call for Proposals details the General Observing (GO) 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 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.
Note: The observing semester 2016A is the last semester NRAO will offer the hybrid configuration, and only the CnB hybrid may be requested.
Considering the lack of future hybrid configurations (after semester 2016A), guidelines on how to substitute such configurations with the use of principal array configurations are presented in the Array Configurations section of the Guide to Proposing for the VLA.
General Observing (GO) and Shared-Risk Observing (SRO)
Summary of Capabilities
As described in the 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 under General Observing (GO). P-band (230-470 MHz) Stokes I continuum observations are also offered under GO. See the Low Frequency Observing section below for more details. Data rates of up to 60 MB/s (216 GB/hour) will be available to all users, combined with correlator integration time limits per band and per configuration, as described in the Time Resolution and Data Rates. However, data rates in excess of 25 MB/s (90 GB/hour) require additional justification. Limitations on frequency settings and tuning ranges are described in the Frequency Bands and Tunability Section.
The GO capabilities being offered are:
| Capability | Description |
| 8-bit samplers |
|
| 3-bit samplers |
|
| Mixed 3-bit and 8-bit samplers |
|
|
Sub-arrays |
|
| Phased-array for VLBI |
|
SRO capabilities can be set up via the Observing Preparation Tool (OPT) and run through the dynamic scheduler (without intervention) but are not as well tested as GO capabilities. A summary of the SRO capabilities being offered are:
- On-the-Fly (OTF) mosaicing‡
- Up to 32 sub-bands per baseband with the 8-bit samplers
- recirculation of up to a factor of 64
- 8-stream recording with phased VLA for VLBA observing.
‡Note: OTF mosaic observations have certain limitations on the length and number of scans. Contact the VLA staff through the NRAO helpdesk to check if the OTF mosaic observations to be proposed are technically feasible ahead of submitting a proposal for the 2016A semester.
We expect that most SRO programs will have no or only minor problems that can be corrected quickly. However, if an SRO program fails and it becomes clear that detailed testing with additional expertise is needed, then the project must make an experienced member from their team available to help troubleshoot the problem. In some cases, this may require presence of that experienced member in Socorro. If adequate support from the project is not given, then the time on the telescope will be forfeited. The additional effort is to be determined based on discussions with the NRAO staff and management and the project team.
Steps to Completion
- Read the 2016A NRAO Call for Proposals description for summaries of the capabilities being offered for GO and SRO.
- If you are proposing for spectral line observations, run the GO Setup Tool (GOST, a java application) to define your correlator set-up and save a snapshot of the tool GUI to disk. Note:
- This observing semester's version of GOST must be run under Java 7; if you have trouble running GOST please contact the NRAO Helpdesk.
- If no GOST window appears please refer to an alternative way to run GOST.
- If you are using multiple monitors please read our special instructions.
- 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 (example of technical justification). In order to determine sensitivities, you will need to use the VLA Exposure Calculator Tool (ECT) to understand what sensitivity you will get for a given frequency, bandwidth, and integration time (guidelines for running the ECT). If you have trouble running the ECT please contact the NRAO Helpdesk;
- 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.
Resident Shared Risk Observing (RSRO)
Summary of Capabilities
The 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:
- correlator dump times shorter than 50 msec, including integration times as short as 5 msec for transient detection;
- pulsar observations;
- data rates above 60 MB/s;
- recirculation beyond a factor of 64 in the correlator;
- P-band system (230 to 470 MHz) polarimetry and spectroscopy;
- 4-band system (54 to 86 MHz; see the Low Frequency Observing section below);
- more than 3 sub-arrays, or sub-arrays with the 3-bit system;
- complex phased array observations (e.g., pulsar and complex VLBI observing modes); and
- frequency averaging in the correlator: a new capability for averaging to wider frequency channels in the correlator has been developed that will reduce the data volume for all continuum subbands
Steps to Completion
- Read the 2016A NRAO Call for Proposals for a summary of the capabilities being offered for GO and SRO. If you want more than what is offered for GO or SRO then you are requesting a RSRO 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.
- Write a scientific justification for your proposal. Note that 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.
- Log into the NRAO Interactive Services page (my.nrao.edu) and click on the "Proposals" tab in the top left to create 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;
- 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 (example of technical justification). Describe what you want to do with the correlator and why this is in the RSRO Category in this section. Contact NRAO staff if you have questions about exactly what is feasible. 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 commission this capability 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.
- 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.
Considerations
A RSRO proposal should contain:
- 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.
- 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. Limited support for accommodation in the NRAO Guest House for participants in the RSRO program may be available.
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.
In general, one month of resident commissioning effort is expected for every 20 hours of VLA time awarded to a RSRO project, subject to negotiation. 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, including time to become familiar with relevant technical aspects. 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 may 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 is possible for a member of the NRAO scientific staff to satisfy the residency requirement on a RSRO proposal. NRAO staff considering providing the residency requirement for an RSRO proposal should consult with their supervisor for further information. Graduate students may satisfy the residency requirement, provided relevant expertise is demonstrated in the RSRO relevant sections of the proposal. Graduate students should be accompanied by their advisor 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.
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 technical development to be undertaken. If the Assistant 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 by submitting an Exploratory Proposal through Director's Discretionary Time. Such visits should conform to the residency requirements above. Proposals to visit Socorro under this program may be submitted at any time.
Low Frequency Observing (P-band and 4-band), and VLITE
The new low frequency receiver system developed in collaboration with the Naval Research Laboratory will be available for Stokes I continuum observations at P-band (230 to 470 MHz) through the GO program. Use of the P-band system for polarimetry and/or spectroscopy will be through the RSRO Program as noted above. The new receivers also work at 4-band (54 to 86 MHz), and new feeds have been deployed on six VLA antennas. Observations at 4-band are also available through the RSRO program.
Finally, the commensal VLITE system will take data at P-band during regular observations that use bands other than P-band. The VLITE system is deployed on ten VLA antennas. Observers wishing to gain access to the commensal VLITE data taken during their VLA observations should follow the instructions on the VLITE web page for doing so.
Documentation Summary
https://science.nrao.edu/observing/call-for-proposals/2016A - The July 1, 2015 NRAO call for proposals for the August 3, 2015 deadline (2016A).
https://my.nrao.edu - The NRAO User Portal. This is a gateway to the NRAO interactive services that include the Proposal Submission Tool (PST).
https://science.nrao.edu/facilities/vla/docs/manuals/proposal-guide/pst - The NRAO Proposal Submission Tool (PST) online manual.
https://obs.vla.nrao.edu/ect - The VLA Exposure Calculator Tool (ECT).
https://science.nrao.edu/facilities/vla/docs/manuals/propvla/gost - The VLA GO Setup Tool (GOST).
https://science.nrao.edu/facilities/vla/docs/manuals/obsguide - The 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.
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.
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