The Design And Implementation Of Indexed Database Based On UCAC2 Catalog

Catalog is a celestial databank which records various parameters (such as location, sports, magnitude, and spectral type). It is a true reflection of the results obtained by the astronomers in the astrometry in certain period. Catalog is the most commonly used astronomical data to astronomers, so in many aspects it is needed to handle and access the catalog, such as asteroid detection. But the data of catalogs are general very large, and they are also continuously increasing with the continuous observation of the astronomers, so it is very valuable to research and implement the efficient access to the catalog.The UCAC2 is a high density, high precision astrometric catalog of 48,330,571 stars covering the sky from -90 to +40 degrees in declination and even going up to +52 degrees in some areas. The data of the UCAC2 is in binary format and the amount of data is relatively large, our observatory's scientific research work, such as searching asteroids and supernova observations both involves the access to the UCAC2 catalog, therefore it has the practical significance of indexing UCAC2 catalog.Currently the UCAC2 catalog only provides the access interface of only FORTRAN and C language, which has certain limitation. And the original indexed file is divided according to ascension and declination, and the access mode is single and lack of necessary unified multi-attribute access interface, therefore, it is very necessary to realize a general data accessing interface and to increase the flexibility of index database are very necessary.After briefly introduced the UCAC2 catalog's file organization, the data structure and the accessing method, this paper introduces the design and development of the multi-index automatic generating system in details, and makes a related analysis to the technique and results used in the system. The main jobs of this thesis are summarized as follows: (1) Introducing the file organization of UCAC2 catalog, analyzing the data structure and the original access method of the catalog. Through the analysis of the original access method, it puts forward a new catalog access method.(2) Introducing the idea of building a multi-index automatic generating system based on the UCAC2 catalog in details. The original access mode is relatively single, this system will realize the efficient access to UCAC2 catalogs through establishing a new index structure and choosing different attributes to establish indexed file. The new index is a two-level index file, which is through the COM technology to produce COM components and to achieve the query function of catalog in different environment.(3) Analyzing the design and development of the multi-index automatic generating system in details. This system is designed and developed in c# based on the.net framework and obtains a good results.