Proposal Conflicts Policy

With the increasingly flexible capabilities being offered on Observatory facilities, there may more frequently be partial conflicts between proposals in terms of source(s), spectral line(s), array configuration (VLA), observing band, correlator/spectrometer set-up, and science goals. For proposals submitted on the semester submission deadlines, proposal conflicts are handled by the normal proposal evaluation and time allocation process. Proposals for DDT, however, may be submitted at any time and may conflict with a proposal that has already been approved through the standard time allocation process, or has previously been observed with the data still proprietary. Under these circumstances, for the overlapping science goals,

  • Any proposal that has been previously approved through the normal time allocation process with priority A or B, but has not yet been observed, will take precedence over the DDT proposal.

  • Proprietary data that have already been observed, including that for priority C and D projects, at the time of the DDT proposal submission will also take precedence over the DDT proposal.

The DDT proposal will be evaluated only on the part of its science goals that cannot be derived from the observations associated with the previously-approved proposal or previously observed proprietary data conflicted with the DDT proposal. If a DDT proposal is approved on these grounds, the DDT team may be given the option of either:

  • employing an observing set-up that does not conflict with the previously-approved or previously-observed proposals, or

  • to use the previously-approved proposal’s proposed set-up; in this case the conflicting/overlapping data will be made immediately available to the proposers of the previously-approved proposal.

The definition of the conflicting/overlapping data is defined in Appendix A.3, and the Observatory utilizes the source list and resources provided in the proposal to determine potential conflicts.

There may be cases where more than one DDT or ToO programs are triggered on the same object nearly simultaneously. Should such a situation arise, the NRAO Director or designee will take the final decision on which program will be observed. Typically, it will be based on the order of proposal submission, with priority given to the first received proposal. Other factors may be considered, including the requested observing frequency and the prevalent weather conditions.