In the early 1980's, the U.S. Geological Survey (USGS), Office of Marine Geology (OMG), Branch of Atlantic Marine Geology (BAMG) in Woods Hole, Massachusetts developed a database referencing the location and content of the numerous data holdings stored on magnetic medium. The database was designed to assist in the indexing, location and retrieval of the data by BAMG personnel. Specifically, the database was designed to allow BAMG personnel to search by various field attributes including, but not limited to, geographic area, data type, year of collection and research vessel. Information retrieved from the database could then be viewed within a graphics display showing the coverage extent of the selected data sets. Though the database and the interactive display have long been replaced by new tools and methods (i.e. Microsoft Access database and Geographic Information System software), the Open-File Report describing the database, retrieval and display procedures also provides detailed documentation describing the data processing programs and numerous data formats used by BAMG during this time period. That information is still referenced and used to support data archival activities and is presented here as a online resource. The more pertinent information regarding data processing programs and data formats has been presented separately for user convenience.
The information presented below has been excepted from Open-File Report entitled MRNIDX - - Marine Data Index: Database description, operation, retrieval, and display. The complete PDF document may be downloaded from Open-File Report 82-397.
A database referencing the location and content of data stored on magnetic medium was designed to assist in the indexing of time-series and spatially dependent marine geophysical data collected or processed by the U.S. Geological Survey. The database was designed and created for input to the Geologic Retrieval and Synopsis Program (GRASP) to allow selective retrievals of information pertaining to location of data, data format, cruise, geographical bounds and collection dates of data. This information is then used to locate the stored data for administrative purposes or further processing.
Database utilization is divided into three distinct operations. The first is the inventorying of the data and the updating of the database, the second is the retrieval of information from the database, and the third is the graphic display of the geographical boundaries to which the retrieved information pertains.
In 1974, the U.S. Geological Survey (USGS) began collecting an increasingly wider variety of marine geophysical data, and a need developed for a centralized depository and index to data collected. In 1976, after the installation of a Hewlett-Packard 2100MX computer system and the establishment of a branch data library, computerized listings were implemented to assist in the inventorying 1 of the data.
As the amount of data collected increased during the next few years, the existing cruise-based inventories became increasingly awkward to use because of constraints imposed by the unit record based upon a "cruise." Given the ever-increasing size of the inventory files and a need for retrieval of information to locate and identify the data, a decision was made to expand the existing inventory files to allow users to make selective, relational retrievals of information on the location and content of requested data. With the conversion of the Geologic Retrieval and Synopsis Program (GRASP) to the Hewlett-Packard 2100MX computer system in 1979, the ability to make selective, relational retrievals of information was at hand. The Marine Data Index (MRNIDX), the subject of this report, is the first automated index to data in which the unit record is defined by the attributes of a cohesive data aggregate stored in a magnetic medium.
The primary purposes of the MRNIDX are to index marine geophysical data collected or processed by the USGS Woods Hole office, and to supply users with information regarding the location, content, and format of the data. The information may then be used for the locating of data to be processed, plotted, or passed along to other agencies. MRNIDX is designed mainly to index data stored on magnetic tape; however, the database format may also be applied to data stored in other forms such as on disk, cassette, and floppy disk.
The database operation is divided into three distinct phases: inventorying and updating of the database as navigational and geophysical data are collected or processed, selective retrieval of information, and a graphic display of the geographical area to which the retrieved information pertains.
Inventorying and updating are the responsibility of those directly involved with database administration. However, the chief scientist responsible for collecting or processing of these data is also responsible for supplying all necessary information to index the data properly.
The second and third phases of operation are the user's selective retrieval of information from the database using GRASP (Bowen, R., and Botbol, J.M., 1975) and the graphic display of the geographical area for which information was retrieved. These programs and their applications are discussed in the section entitled "Data Retrieval.
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