Requirements

In order to make best use of ALMA we need to change the observing schedule according to the system status and the weather conditions. For example, if the weather is not good enough for the current project to succeed, then we make better use of the array by scheduling a project which can make use of the current conditions. We might call this level 1 dynamic scheduling, where only the time allocation is changed, but the observing procedures are specified within the previously prepared observing scripts for each project. Level 2 dynamic scheduling allows system control of the observing procedures (calibration sources, integration times and calibration intervals, etc) depending on the weather and system parameters.

A flexible, dynamic schedule accommodates both fixed queue and interactive observing. Time critical observations are scheduled by giving them high priority at the appointed time. Interactive observations are made more productive by the use of beakpoints; the user takes control of the telescope for a time interval after which control is returned to the scheduling program to determine the best project to observe.

The user may also wish to modify the observations as the results become available from the on-line pipeline analysis and image production. An interactive observer (local or remote) can make these decisions in real time or may wish to dynamically schedule observations based on pre-determined outcomes from the data. For example, if source A is detected, then spend more time on source B, or to change the mosaic pattern or frequency band.