Search and Location of FITS Data Files

Flexible Image Transport System(FITS) is the widest adopted data format in astronomy. Since FITS was endorsed by the International Astronomical Union(IAU) for the interchange of astronomical data in 1980s, most of astronomical data are stored by and exchanged among astronomers and world-wide data centers. FITS files, stored and managed by Operation System(OS) file systems, can hardly be searchable and locatable. With the rapid increase of the number of FITS files, and development and popularization of Virtual Observatory(VO), it is more and more urgent to provide on-line search and access functions for FITS files stored in file systems. The keywords records in FITS header provide exact description of the structure of the corresponding FITS file, but also give much important information of the data stored in the file. Most of search requirements on FITS files can be satisfied by information taken from primary header keyword records. Storing and managing keyword records using DataBase Management System(DBMS) will make FITS file searching easily and flexible. FITS Header Archiving System(FitHAS) is a simple but useful application developed by Chinese Virtual Observatory(China-VO) project. With FitHAS, the keyword record information for one or more FITS files under a given directory can be imported into a database easily. Basing on the keyword database, FITS files can be searched and located. A little further, advanced data access systems including VO can be deployed. In the paper, basic knowledge of FITS and FITS header are introduced, searching and accessing of FITS files in VO environments are discussed, and functions, characters, design and development of FitHAS are described.