Design of a Naval Research Laboratory (NRL) system for area of interest access to large volumes of bathymetric data

The Digital Mapping, Charting and Geodesy Analysis Program (DMAP) of the Naval Research Laboratory (NRL), in an effort to aid Naval Oceanographic Office (NAVO) data processing needs, has developed a system to spatially index and query bathymetric data stored in generic sensor format (GSF) data files. The GSF data file format has the ability to store various types of data, but in this system only bathymetry, specifically, single-beam and multi-beam bathymetry, is indexed. Bathymetric data is used by NAVO to generate various oceanographic information products. Presently, to obtain bathymetric data for a particular area of interest (AOI) for product generation, NAVO personnel must determine which oceanographic surveys generated bathymetric data files in the AOI and where these files are physically located. Next, they have to download all of these files and process them. Each of these files may have large amounts of data (potentially hundreds of megabytes) that are outside of the given AOI. It is also possible that some files may not have any data in the AOI. Using the spatial indexing ability of Oracle, the NRL-developed system allows NAVO to quickly determine and retrieve only the bathymetric data that are relevant to the AOI, completely automating the process of data acquisition. This system provides benefits by substantially reducing the amount of data that must be considered when producing a product and also by providing users with an intuitive interface to use for data retrieval purposes. This paper discusses the spatial indexing scheme, spatial querying, the interface for retrieving data, and other components of the NRL system. In addition, problems that were encountered and the time savings provided by this system are discussed.