Scheduling In Astronomy

Abstract

The scheduling of proposals for astronomical observations is a complex problem, which is being treated in various ways since several decades. Although most of the modern professional observatories use certain degree of scheduling automation, there is still a huge part of human intervention to build up the daily plan, and to take last minute decisions, due to atmospheric conditions, technical failures, etc. These external parameters can vary at any time during observations, and therefore a dynamic re-scheduling is needed. In this case, external parameters can cause priority changes, as some observations may not be anymore suitable to execute under the new conditions. Moreover, as proposals depend on the visibility of the astronomical source to be observed, they might be only valid during certain day/night time, and/or during a certain period of the year. Therefore, it may happen that initially high priority tasks have to be executed with a less priority, or can not be executed at all within one observations period. Particular proposals may also depend on others to be executed.