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Time Allocation Under the Long Baseline Observatory (LBO)

Because of the reorganization among NRAO, the LBO, and the Green Bank Observatory (GBO), this 2018B Call for Proposals is only for observations with the VLBA/HSA and the GMVA ;  the call for the GBT and the VLA can be found at the GBO Call for Proposals and the NRAO Call for Proposals, respectively. For the meantime the LBO, GBO, and NRAO will continue to run a single, joint proposal review and time allocation process, as described here.

Large Proposals

The VLBA continues to encourage Large proposals (those requesting 200 hours or more).  The Large BeSSeL parallax project was completed in semester 2016B; the Large GOBELINS (Gould's Belt) parallax project will mostly be completed during semester 2018A. The completion of these two Large proposals has (and will) free  considerable observing time, especially in the highly coveted Galactic plane parallax slots.  VLBA proposers are urged to submit their Large proposals for this Call,  or to submit relevant pilot projects that will be useful in preparing for a future Large proposal.

VLBA Shared Risk Observing

The VLBA Shared Risk Observing program allows users access to capabilities that have been commissioned but are not completely tested.  The following capability is offered under the SRO program in Semester 2018B:

  • VLBA Raw Data Copying - a limited amount of raw, recorded data from a user's observation can be copied onto user-supplied media storage.  Proposers interested in this capability should contact the NRAO helpdesk with their questions.
For further details on this new capability and others in the Shared Risk Observing program, visit the VLBA SRO web page.

VLBA Resident Shared Risk Observing Program

The VLBA Resident Shared Risk Observing (RSRO) program provides users with early access to new capabilities in exchange for a period of residency in Socorro to help commission those capabilities. For example, the phased-VLA system was developed through RSRO programs.  Users are encouraged to conceive and propose innovative ideas for new VLBA capabilities.  Some staff suggestions are  included at the VLBA RSRO program page, along with details for submitting RSRO proposals.

Proposers should be aware that RSRO capabilities are generally not approved at priority A, owing to the level of risk associated with these observations.

Other Proposal Opportunities

Proposers should keep in mind that the following classes of observations are very welcome, as well as Large Proposals (see above):

  • Director's Discretionary Time Proposals:  Proposals for Director's Discretionary Time (DDT) may be submitted at any time.  They must be submitted through the Proposal Submission Tool, and are intended to address targets of opportunity, high-risk/high-return exploratory time, or other science opportunities deemed sufficiently urgent to justify prompt action.  For pre-planned observations of possible transient events, whose event times are unknown a priori, a Triggered proposal submitted at a regular deadline is preferred over a DDT.  See the Proposal Types web page for further details.
  • Filler Programs: Some programs are not time critical, do not require highly subscribed GST ranges, or can usefully observe in multiple brief, randomly-timed sessions. Such programs may be able to take advantage of "filler" time.  Types of projects that might be suitable for VLBA filler time include: surveys of many sources, deep integrations spread over many sessions, and long term monitoring.  It is rare for fewer than 6 antennas to be functional and have good observing conditions as well; high frequency projects that can use a reduced array are therefore viable.  To be eligible for FILLER status the project should be flexible enough to be scheduled:
        with non-ideal weather conditions;
        with less than the full complement of antennas;
        with a target list of source positions around the sky; and
        with short duration or variable length scheduling blocks.
    Proposals for filler projects must include the word "filler" in the proposal title.  Teams must provide tools that allow VLBA operations, with minimal effort, to create schedules for arbitrary blocks of time of one hour or longer when such time becomes available during dynamic scheduling.  Large VLBA filler proposals, and multi-semester proposals, are also welcomed.   Pt_LST ranges  07 - 13 hours and 23 - 03 hours may have less competition for time.
  • High Risk Proposals: As a means of maximizing its scientific impact through cutting-edge observations, the Observatory strongly encourages the submission of high-risk/high-reward proposals.
  • Commensal Observing: The VLBA has some innate ability to support commensal observing either through clever use of existing infrastructure or through operation of user-supplied capabilities.  It is recommended that interested proposers discuss their ideas with VLBA staff prior to submission in order to develop a plausible program.  Such observations will be subject to resource constraints.

Further information about each of these programs can be found here.  If, after reading pertinent documentation, there are still questions, please submit the questions to the NRAO helpdesk.

VLBA Saint Croix Station

The VLBA Saint Croix station (Sc) in the U.S. Virgin Islands remains, as of this writing (late December 2017), unable to participate in normal VLBA operations, mainly because of intermittent power and communication problems on the island.  Plans are proceeding for a team to visit the station to clearly assess the work required to restore the station to operational status.  At this time, we fully expect that the station will be available for normal operations during the 2018B observing semester.