Outcomes and Disposition Letters
A Disposition Letter is sent to the PI and co-Is for semester and DDT proposals. Disposition Letters are also available in the PST for proposers to review. For the semester proposals, this letter contains comments from the cognizant SRP, a linear-rank score from the SRP, comments from the feasibility review (if available), comments from the TAC (if available), and the scheduling priorities. For DDT proposals, this letter contains a brief notice of approval or justification if declined.
A scheduling priority is assigned to each session of a proposal, which is guided by the outcome of the SRPs (e.g., linear-rank score) or the Observatory Site Review, and takes into account the time available on a facility. It is the policy of the Observatory to not allocate all of the available observing time in any LST/GST range during any semester to a single proposal; this includes Joint Proposals. There are five different scheduling priorities:
| Priority A | This is the highest scheduling priority; the observations will almost certainly be scheduled. For the GBT and the VLBA, the observations will be considered for scheduling for up to two semesters. For the VLA, the observations will be considered for scheduling for two VLA configuration cycles5. |
| Priority B | This is the next highest scheduling priority; the observations will be scheduled on a best effort basis. For the GBT and VLBA, the observations will only be considered for scheduling for one semester. For the VLA, the observations becomes ineligible when the associated configuration ends. |
| Priority C | A lower scheduling priority; the observations are not guaranteed to be scheduled and are used to supplement gaps (e.g., filler time) in LST/GST ranges not filled by higher priority proposals. For the GBT and VLBA, the observations will only be considered for scheduling for one semester. For the VLA, the observations becomes ineligible when the associated configuration ends. |
| Priority D | The lowest scheduling priority; the observations have a low probability of being scheduled and are used as secondary filler when higher scheduler priorities cannot be scheduled. For the GBT and VLBA, the observations will only be considered for scheduling for one semester. For the VLA, the observations becomes ineligible when the associated configuration ends. |
| Priority N | The observations will not be scheduled. |
The scheduling terms described above apply unless explicitly stated otherwise in a Disposition Letter. Disposition Letters may include a Scheduling Priority marked with an asterisks (∗; e.g., N∗); this is used to indicate that there are specific comments from the SRP, TAC, or Observatory Staff to the proposing team regarding the requested resources. Proposers should review the comments that are returned in the Disposition Letter before proceeding to observation preparation (Section 5.1). In the event that clarification is needed about technical comments, please submit a ticket to the NRAO Science Helpdesk and select the “VLA/GBT/VLBA Proposal Review” topic.
The outcome of the proposal review process is final. If an unfavorable disposition is received, the Observatory strongly encourages authors to prepare a new proposal for a future semester that addresses the returned comments. It is the policy of the Observatory to not allow communication between science reviewers and authors, even mediated through a third party such as the Observatory staff.
In case of questions about details in the Disposition Letter, please submit a ticket to request clarification through the NRAO Science Helpdesk and select the “VLA/GBT/VLBA Proposal Review” topic. However, in no case will such a request lead to a revision of the linear-rank or scheduling priority assigned to the proposal as a result of the review process.
5 See the definition of a VLA configuration cycle in Section 7.1
