TAC Report for Semester 2012A
The ProcessThe Observatory has completed the second semester of the new proposal evaluation and time allocation process for the Expanded Very Large Array (EVLA), the Very Long Baseline Array (VLBA)/High Sensitivity Array (HSA), and the Green Bank Telescope (GBT). A total of 400 proposals were recieved at the 1 August 2011 submission deadline for Semester 2012A. In aggregate the proposals covered the broad spectrum of modern research in astronomy and astrophysics. Proposals were assigned to one of eight science categories and released to the relevant community-based Science Review Panels (SRPs). Proposals also underwent technical reviews by NRAO staff. Reviews were completed in October 2011 and then cross-reconciled by the Time Allocation Committee (TAC) during its meeting in Green Bank, WV, on 2-4 November 2011. A new Proposal Handling Tool (PHT) supported the TAC's consideration of EVLA and VLBA/HSA proposals. The TAC consists of the chairs of the SRPs and is charged with recommending a science program for Semester 2012A to the NRAO Director. After approval of the science program, a disposition letter for each proposal was prepared and sent 6 December 2011 to all authors of the proposal. A TAC report (this document) containing information for proposers and observers, including statistics and telescope pressure plots, was released the same day. The approved science program will be posted soon. The Observatory welcomes community feedback on its new process for proposal evaluation and time allocation. Please provide such feedback via the Proposal Review department of the Observatory's Helpdesk.
Science ScoresLinear-rank science scores are assigned by the SRPs. The Observatory uses a scale from 0 to 10 to score proposals. A science score of 0 corresponds to an outstanding proposal. A science score of 10 corrresponds to a very poor proposal. The quartile boundaries for the science scores are 2.5, 5.0 and 7.5.
Scheduling PrioritiesThe Observatory's telescopes are predominantly dynamically scheduled. Guided by the SRP science score and taking into account the time available for each telescope, the TAC assigns a scheduling priority to each session in each proposal. Possible scheduling priorities are: A = the observations will almost certainly be scheduled
B = the observations will be scheduled on a best effort basis
C = the observations will be scheduled as filler
D = N = the observations will not be scheduled (explicitly rejected by the TAC)
NS = the observations will not be scheduled (not schedulable so rejected by the TAC)
NA = not available because the proposal is being held for consideration at a future TAC meeting The tables below provide statistics by proposal counts and by proposal hours. Entries are binned according to time approved at scheduling priorities A or B, time approved at scheduling priority C only, and no time approved.
Pressure PlotsFor the GBT, the plot below shows the proposal pressure for time granted in Semester 2012A. The plot does not include all hours allocated for VLBI observations. Only the central LST hour of each session was used in creating this plot - the corresponding plot for how the time will actually be scheduled would be smoothed by 3-6 hours. The y-axis ranges from 0 to 323 hours.
For the EVLA, the pressure on dynamic time as a function of LST is shown in the pressure plots below for the C, CnB and B configurations planned for Semester 2012A. The plots encode pressure by scheduling priority, as well as by frequencies above 10 GHz (light shading) and below 10 GHz (dark shading). The time available per LST hour is shown by the black line. Engineering and commissioning activities cause the thick black line to be less than the total number of LST days in the configuration. Such activities dominately occur during daytime, causing the black line to dip for daytime LSTs.
Observation PreparationFor the GBT and VLBA, Semester 2012A spans 2012 February 1 through 2012 August 31. Those with allocations should begin observation preparation soon. Procecedures are described at GBT and VLBA. For the EVLA, Semester 2012A involves the C, CnB and B configurations. Observers are reminded of the shared-risk nature of early science. Observing restrictions are evolving with time, so observers should wait until a few weeks before the planned start of a configuration to begin observation preparation. Consult the relevant pressure plot above when preparing scheduling blocks as described at EVLA. Scheduling blocks that are not observed during a configuration will be expired at the planned end of the configuration. Unless stated otherwise, any time allocated is only for the identified proposal, and no modification in the project should be made without obtaining permission from NRAO scheduling staff. To seek permission, submit a ticket to the Proposal Review department of the NRAO Helpdesk. Page maintained by schedsoc
Modified on Wednesday, 07-Dec-2011 14:44:51 MST