LAMOST Observatory Control And Data Acquisition System

The Large Sky Area Multi-Object Fiber Spectroscopic Survey Telescope (LAMOST) is a world's leading Spectroscopic Survey Telescope. Its large diameter and large viewport give it strong capacity to spectrum sky surveys. LAMOST is a most complex system which consists of several subsystems. It can hardly be taken into observation for its complexity without the Observatory Control System (OCS) which provides automatic observatory control. OCS is the top-level control system software of LAMOST. The main purpose of OCS is to manage, coordinate and control the subsystems of LAMOST and make the whole telescope work in an orderly manner. According to the plan, astronomical observation will be carried on step by step. It is a concentrated and scattered observatory control system upon all software and hardware modules with interfaces in multi-level. As the control software of the world's leading large telescope, OCS is also a complex software system with few precedents. Research on LAMOST observatory control involves software development, physical course of observation process, data exchange with subsystems, system testing work, etc. The analysis of these issues and solutions not only helps make progress with the LAMOST Project but also bring valuable experience and documents to later work.The control of LAMOST observation is a combination of controlling subsystems. The main idea of OCS is to control subsystem by commands, which is called Command-drive Model. In this model control of subsystems is described as a roller-order process with command—feedback—command steps. Based on the Command-drive Model, protocols of command-received/refused and command-execute&feedback are established which help OCS command and readout from subsystems.Under the ideas of module-reuse and framework designment, OCS is designed to a distributed system with components and modules. So it is easy to work along and upgrade. However, control of observation is a course of observation process. There is a detailed description of OCS kernel modules in this dissertation, which is based on implement of observation process.With LAMOST progress, the mini LAMOST is on schedule. Research on applying OCS to the mini LAMOST is promoted after introduction to the mini LAMOST. User GUI is developed. According to requirements of coming to use of OCS and software development course, a systematic and comprehensive test is carried on to OCS version 2.30. Then the dissertation raised plan and forecast to online test of OCS in the mini LAMOST.The subsystems include Survey Strategy System (SSS), Telescope Control System (TCS), Instruments Control System (ICS), Data Handling System (DHS), Weather Information System (WIS), etc. DHS is designed for transporting commands from OCS to CCD systems and handling data from CCD systems. In this dissertation a data readout and storage model is built with interface methods and basic commands and parameters defined, which present preliminary research to accomplishment of DHS.By the end of the dissertation there are further discussions about optimization of the distributed model and data model of OCS by detailed analysises of the advantages and feasibility of them, which lay a good foundation to the continued development and improvement of OCS.The dissertation is composed of seven chapters. The first chapter introduced the background and scientific goals of LAMOST project. It described how LAMOST works and why OCS is a certain choice.The second chapter described the system model and framework of OCS. The purpose of OCS is to accomplish observation process by controlling all subsystems. It works on the Command-drive Model in a distributed style under CORBA architecture. OCS development environment and interfaces between OCS and subsystems were introduced at the end of this chapter.Chapter III focused on OCS kernel modules, including Command Executor, Message Bus, Subsystem Agents, etc. Each module has its functions in the LAMOST observation process. Detailed analysises are described on them.Chapter IV introduced effective work on the mini LAMOST OCS which is based on OCS version 2.30. It includes development and implement of Observation Control Console, testing work of OCS-2.30, analysis of coming OCS online test in the mini LAMOST, etc.Chapter V designed the data framework of DHS and CCD systems. Discussion about it led to the Twin-distributed Storage Model. Also, interface and basic commands with their parameters were defined.Chapter VI brought new ideas to original OCS distributed model and data model, which are discussed in detail.Chapter VII is a summary and prospect of this dissertation. It reviewed work of this dissertation and brought forward proposal for continued research and development of LAMOST OCS and DHS.The appendix is technical documents used in development of OCS. Most of them were translated, collected or written by the author.The last part is reference and the articles published during student course.The original points or ideas of this dissertation are listed following:1) Based on early research and design work, the implement of OCS version 2 reached the engineering requirements. The software passd the project test and received acceptance. 2) Applying OCS-2.30 into the mini LAMOST by analysis and discussion. Firstly using physical experiments in OCS software module testing work to examine if OCS could meet the LAMOST system's physical requirements.3) Preliminary research on DHS with its framework established. Firstly declare the Twin-distributed Storage Model in LAMOST, which resolved the problem of parallel readout of large size data from CCD. These data will be stored in DHS and shared through the Twin-distributed Storage Model.