ATIS: User to PAC to AT

The Principal Astronomer's Computer to Automatic Telescope Link

In the link between a PAC and an AT, ATIS links one telescope (an AT) to the individual responsible for the operation of that particular telescope (the PA). In this link, ATIS does not carry information about the scientific relevance of the requests. ATIS states how an automated telescope reacts to a given instruction, but the details of how the telescope executes the instruction are not defined. It is assumed that the operation of the telescope will be totally automated. The level of automation used in the generation of ATIS input files and the reduction and storage of ATIS output files is determined by the PA. ATIS allows the PA to design observing programs with adjustable levels of control and priority and can leave the telescope control system the freedom to adjust for variable execution time or interruptions of the observations caused by clouds or other conditions, or it can exercise complete and exact control.

An attempt has been made to keep the statements in a form not unlike those which an astronomer might pass to a human telescope operator who knows how to operate the telescope but who has no knowledge of the scientific goals of the astronomer. This does not make compact files, but simplifies the debugging of problems. Standard compression programs can make ATIS files compact. It is not expected that humans will directly generate ATIS files directly with an editor, although it could be done.

ATIS is designed to grow to allow added capabilities desired by users. If a capability is needed within ATIS which does not exist in the standard, users are encouraged to add these capabilities to their particular project. If these capabilities might be of use to others in the astronomical community users are encouraged to submit these modifications as proposed standards for future ATIS revisions. The users of ATIS should remain in control of what is placed in the standard. The ATIS standard should be revised no more frequently than once per year and is suggested that ATIS revisions carry the year as a reference to the revision. The original version of ATIS was published in 1989 and will be referred to as ATIS89. This version will be referred to as ATIS93.

Capabilities added in ATIS93 which were not in ATIS89 include improved time scheduling, the provision for real time interaction between the PAC and the AT, statements for communications between users and PAs, and statements for operating instruments containing CCD detectors.

The User to Principal Astronomer's Computer Link

This portion of ATIS is completely new in ATIS93 and should be considered experimental. It is referred to as the Goal Oriented Astronomical Language (GOALS). It is designed to provide a means for users to express their requests for scientific observations to a PA (or to the surrogate PAC). It also provides a means to return the results of the observations in a meaningful way to the users. At the time of this standard, there are no users currently using this portion of the standard. The primary reason for providing this section was to remove some of the burden of detailed interaction between the PA and the users and to allow the design of an effective scheduler by providing a language for stating astronomical goals in a semi-formal manner.


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