Thirty Meter Telescope: observatory software requirements, architecture, and preliminary implementation strategies

The Thirty Meter Telescope (TMT) will be a ground-based, 30-m optical-IR alt-az telescope with a highly segmented primary mirror located in a remote location. Efficient science operations require the asynchronous coordination of many different sub-systems including telescope mount, three independent active optics sub-systems, adaptive optics, laser guide stars, and user-configured science instrument. An important high-level requirement is target acquisition and observatory system configuration must be completed in less than 5 minutes (or 10 minutes if moving to a new instrument). To meet this coordination challenge and target acquisition time requirement, a distributed software architecture is envisioned consisting of software components linked by a service-based software communications backbone. A master sequencer coordinates the activities of mid-layer sequencers for the telescope, adaptive optics, and selected instrument. In turn, these mid-layer sequencers coordinate the activities of groups of sub-systems. In this paper, TMT observatory requirements are presented in more detail, followed by a description of the design reference software architecture and a discussion of preliminary implementation strategies.