The allocation of AAT time uses two parameters to balance rightful AAT share with high-quality science:
- 1. A specified fraction, fO, of open-access time,
taken out of Australia's
(otherwise unconstrained) share, fA,
such that fA+fO=1. The purpose of the
open-access share is to foster international collaboration, as well as
allowing high-ranking but internationally-dominated proposals to also use
2. A super-majority threshold, M, used to measure the proportion of
Australian involvement in a proposal. The purpose of the super-majority
threshold is to ensure that time is awarded largely according to Australia's
funding of the AAT's operation while still allowing (and even encouraging)
some level of collaboration.
The new time allocation procedure starts (as it always has) with the Australian Time Allocation Committee (ATAC) ranking all proposals by scientific merit, without regard to the nationality of the applicants. The AAO's scheduler then proceeds by:
- Initially drawing upon the Australian and Other time shares in proportion to the fraction of such proposers on each program. A proposal that is awarded N nights and has A Australians and O Other proposers counts as NA Australian nights and NO Other nights, where NA = N.A/(A+O) and NO = N.O/(A+O). Then:
- If the Australian share is exhausted first, the remaining proposals are awarded time as ranked, regardless of nationality, or:
- If the Other share of AAT time is exhausted first, the remaining proposals are only awarded time from the residual Australian share if they (i) they have an Australian PI and (ii) meet the super-majority criterion - i.e. if the fraction of Australians is greater than or equal to the super-majority threshold, A/(A+O) ≥ M, rounding to the nearest whole percentage. The exception to this is when there are no qualifying proposals that can make use of the remaining time due to observational constraints.
Presently ATAC adopts a Australian fraction of 70%, and an Other
fraction of 30% (including the OPTICON transnational access program). The
Australian super-majority threshold will be 67%.
These fractions reflect AAT demand (based on
nationality) over the past few semesters and are supported by the AAO User's
Committee and AAT Board. They are not necessarily fixed and will be reviewed
in the context of AAT demand over future semesters.
Matthew Colless and Heath Jones 20 July 2010