A. Belokonny, S. Kurbatov, O. Molchanov, A. Lobzin

The article describes a model implementation of the access to scientific data, a large volume. Noted the specifics of scientific data, a large volume and difficulty of the full solution of the tasks of access to such data with the help of modern computer and information technologies. An approach is proposed for access to scientific data of a large volume, using as the basis of a hierarchical file system. This system differs reliable hardware and system software equipment, the orientation of the General problems of storage and processing of data, approbation on the volume of data to multiple petabytes. Over the basic system is proposed to organize a specialized software with advanced capabilities for use of metadata and a high-level query language. For testing of logic of interaction with the base system has developed a model, implemented in client-server version. On the client side model includes HTML pages, which provide a variety of opportunities formulations of queries. On the server side model includes a relational database, used as a tool of work with metadata and as a directory of files with scientific data. The logic of work with the model assumes the creation of ontology, which at a high conceptual level describes the data model and provides interpretation of requests for search and processing of scientific data, a large volume. The proposed approach is aimed at finding more adequate to the requirements of science and less expensive solutions. Describes the General scheme of the model and examples of queries using the metadata file format FITS. Possibilities for linguistic processing of requests. Briefly describes the service functions of the model and the results of preliminary testing. Determines the way of further development of the approach, which implies the embodiment of decisions, used in the modelling process, in the framework of the real hierarchical system and the substantial development of semantic component.