Scheduling Data

An observing program is defined by the following items:

• Program ID, principal investigator name, institutional affiliation and country

• Instrument (which implies the telescope configuration, e.g. cassegrain or coude)

• Amount of time required (integral or half day)

• Moon preference - this can be expressed as the number of days from new moon, or more simply as one of ``bright'', ``dark'' or ``no constraint''.

• Target visibility preference - this can be expressed as preferences on particular months, or a range in right ascension and declination for the targets.

• Time Constraints - this expresses time intervals where the observations can occur and can either be expressed as dates to be included or excluded from consideration.

• Relative constraints between program, e.g. program 2 after program 1 or group two programs within a time interval.

• Priority assigned by observatory or time allocation authority.

For CFHT scheduling, the input data was provided in a tabular text file with each program defined in a row and each column corresponding to a parameter. A simple function converted this information to the generic input format used by the Spike scheduler.

In addition to the program information, it is necessary to define the start and end dates of the scheduling interval (typically a 6 month semester) and any reserved times where no observations are made (e.g. major holidays or engineering times). An additional input is a description of the telescope instrumentation (e.g. instruments and associated telescope foci) and constraints on instrument changes (e.g. some instrument changes may require a half-day or more of ``down time'' or a limit on the total number of upper-end changes in a semester).