Scheduling Procedures

Scheduling is formally done quarterly. Preceding every quarter, Deputy Director Ben Williams emails the institutional schedulers with their institution’s allocation for the upcoming quarter, broken down into bright, gray, and dark half-nights. The institutional schedulers adjust the proposals from their institution's observers so that the total requested half-nights match the allocation for the quarter, including the proper number of bright, gray, and dark halfs. In addition, the institutional schedulers must rank their institution's proposals, with the knowledge that the highest ranking proposals receive the highest scheduling priority. The institutional schedulers send the adjusted and ranked proposal cover sheets to Ben and to Russet McMillan, and Russet assembles the schedule starting with the highest ranked proposals. This is a complex task that often requires several iterations, but the underlying goal of this effort is to try to accommodate everyone’s requests as best we can.

This formal process needs to be followed initially each quarter to produce a balanced schedule. However, once the initial schedule is issued, each quarter there is some room for flexibility built into the schedule. We try to accommodate special requests from institutions for time trades between quarters, open time, and director's discretionary time, but such requests should be made to the institutional scheduler, Director Nancy Chanover, Ben Williams, and Russet McMillan, outside of the formal scheduling process.

In order to make sure that this process is fair and equitable to all users, we ask that you adhere to these policies:

• The PI of each proposal must have an official affiliation with an ARC institution or leasing partner.
• Only trained observers should operate the telescope remotely through TUI. Untrained observers may work remotely if a trained collaborator is assisting them, or they should plan to make their observations in an on-site training run.
• Institutional requests to the initial schedule for each quarter should match the institution’s allocation. However, the institutional scheduler may also indicate which programs are flexible and able to make use of brighter moon than originally allocated, in order to accommodate other scheduling needs. We will do our best to accommodate such requests based on the demand.
• If requests are lower than the allocation, this puts an institution at higher priority for open time. Worse-than normal time losses in a previous quarter or month due to weather or equipment problems may also increase priority when requesting open time. But any ARC-affiliated observer may ask for open time, and requests will be considered as they are received.
• Fractional-night requests will only be honored if there is a strong science driver for shorter time slots. Flexible programs may volunteer to be paired with fractional programs in exchange for short slots on additional dates, which may improve weather odds. It is helpful if institutional schedulers with one or more fractional-night programs identify other flexible programs within their institution to share some of the time, even if that may not be the eventual scheduling solution.
• Observers needing to change their scheduled time may arrange a trade within their own institution by working with the other observer(s) involved and their institutional scheduler, and then notify the observatory schedulers (Ben Williams and Russet McMillan) after the arrangement is made. To prevent unfair or excessive trade requests, potential time trades with a program from another institution should be arranged by request to the observatory schedulers together with the institutional schedulers, rather than by direct contact between observers in different institutions. Please give as much advance notice as possible.
• Observers can request Target of Opportunity (ToO) half-nights in their institutional proposals. These will be scheduled as dark half-nights late in the quarter. If a time-critical event occurs and they wish to trigger their ToO observation, an approved program observer can contact the observing specialist that is working that night for a same-night interruption. If they would prefer to wait a night or two, they can contact Russet or Amanda to update the schedule for the half-night they will preempt. Only programs designated as “Normal” in the ToO Status column of the monthly schedule can be preempted. If the ToO iprogram attempts to trigger on a “Protected" program, their trigger will be refused and they will need to wait until the first unprotected half-night to observe. Once the preempted program has been informed that their time will be reallocated to a ToO program, the ToO program will give their originally-scheduled half-night to the preempted program, even if the preempted program only loses a small part of their original half-night. If the ToO program does not use their trigger, they can use the scheduled time for other science at the end of the quarter, or forfeit it to other users. In the event of a forfeit, users at the same institution as the ToO program have first opportunity.

All schedule changes after the initial schedule for the quarter is produced lie outside of the initial allocations for the quarter. Thus OPEN/DD time is not formally charged against an institution's allocation. One strong reason why we broker them all through Nancy, Ben, and Russet is to keep them as fair as possible.

Again, the aim of these policies (none of which is new) is to ensure a fair and equitable telescope schedule that is optimized to best meet the science needs of the 3.5m user community. Please share the user-related information with the users at your institutions so that everyone is aware.