Data Base Structure to Support the Production of the Digital Bathymetric Data Base.

摘要

NORDA was tasked to develop a computer model that would support the storage and retrieval of the 7 billion points of collected bathymetry that are used to support the Ocean Survey Program. These data points are stored at a resolution that is beyond the noise level induced by the collection sensors. Gridding these bathymetric data on an acceptable resolution of 0.1 minute for areas of actual coverage can greatly reduce storage requirements. Further reductions can be achieved through the use of the compression algorithms developed as a result of this project. An overall compression ratio of 500 to 1 was demonstrated using actual data supplied by the Naval Oceanographic Office. Once the data base is reduced in size to a manageable level, relational data base management systems become practical for organizing information related to the bathymetry in order to provide easy multikeyed access. The Structured Query Language, a de facto standard for data base retrieval, can be used to query the data base to obtain tables of path names for the files that contain the compressed bathymetry. A suggested format for these files and the relational data base structure is presented. Keywords: Bathymetry prototypes; Data compression. (MM)