A software interface between scientific data formats (SDF's) and wide-area data-base search-engine software has been developed to provide seamless access to data used in support of NASA projects. Most SDF's are known or understood by only a select audience. These SDF's are also only searchable using specialized tools unique to that particular SDF. This type of data storage and retrieval system excludes occasional users or management from easily accessing data products. Therefore, a simple access to data products has been developed based on the web browser paradigm.

Typically, a single host tracks data products using a commercial relational data-base management system (RDBMS) or custom file-based data base. With this type of (DBMS) data base management system, only references to products and fixed-file descriptors are allowed for data storage and retrieval. For this reason, a viewable data dictionary coupled with standard and familiar search tools were used to remove these limitations.

This innovative technology is a Search Engine System for Scientific Data Formats. It exists as several government off-the-shelf software (GOTS) and commercial off-the-shelf software (COTS) products, integrated to form a single, logical host for a distributed search tool.

This state-of-the-art search engine has been running on a developmental web site. Here, the webmaster designates an SDF directory, which is the repository for SDF files. The SDF directory is input to a translator program, which runs automatically with the webmaster's user name and privileges. The translator program extracts certain data, such as variables, attributes, file descriptions, time stamp, and a uniform resource locator (URL) for each SDF found in the tree below the specific directory. It then converts this data to a Hypertext Markup Language (HTML) document. The time stamp is used to update the HTML document if an SDF file changes. The system periodically submits new or changed URL's to commercial search engines. This system also allows nontext search extensions.

The capability to search the data dictionary of SDF's is a key innovation. Users who are unfamiliar with a library's structure are able to gain access to that structure, allowing them judge a data product's value.

The union of a WAN DBMS to SDF's is a second innovation. The WAN DBMS interfaces various search engines to the internally self-describing SDFs. This allows remote users to search SDF's using data element names, types, and values.

Simplified access to complex data bases lets users explore data intuitively. This enhances the value of the data by increasing their usefulness to the scientific community.

This work was done by John T. Robinson and Steven Pham of SARA, Inc., Electronics and Information Systems Business Area, for NASA's Jet Propulsion Laboratory.For further information, contact John Robinson, SARA, Inc., 15262 Pipeline Lane, Huntington Beach, CA 92649-1136, Telephone: (714) 373-5509. NPO-30036


NASA Tech Briefs Magazine

This article first appeared in the January, 1998 issue of NASA Tech Briefs Magazine.

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