Where did these data come from?
Why transfer the 9-track data to CD-ROM?
If the data were currently unused, why save
them?
If the data are so important, then why not save
all the tapes?
How were the tapes transcribed?
Where did these data come from?
This CD-ROM contains navigation and geophysical data (gravity, magnetics and bathymetry) collected and processed by the U. S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Field Center, Woods Hole, Massachusetts. Data were collected during a total of 12 cruises utilizing the R/V H.J.W. FAY during the years of 1975 and 1976. Approximately 100 of the 280 9-track tapes collected during the cruise and later post-processed at the Center were transcribed from 9-track media to ASCII files and stored on this CD-ROM for archival purposes. The majority of these tapes were originally recorded as 800-BPI while a few of the transcribed tapes were recorded at 1600 BPI.
Why transfer the 9-track data to CD-ROM?
A decision to transfer the data from the old 800-BPI and 1600-BPI tapes was made for several reasons. The first and most significant reason concerned the quality and physical characteristics of the tapes. Many of these tapes were approximately 15 years old and had been archived in Center's data Library unused for a majority of this time. In addition to the age of the tapes, the lower tape densities of 800 and 1600 BPI were no longer considered standard. Most computer sites, including this Center, no longer maintained tape drives capable of reading the lower tape density. Therefore, the age, density and shelf life of the data tapes were considered of paramount concern to warrant transferring the data to CD-ROM.
A second reason for transcribing the data tapes to CD-ROM was to alleviate storage problems being encountered in the digital tape library. The space allocated for Center’s tape storage is finite and filled almost to capacity. A more compact and efficient archive medium was desired.
The third and final major reason for transcribing the data tapes to CD-ROM was to document the R/V FAY cruises and data so the information could indeed be utilized in the future. In addition to the actual data, an attempt to include documentation that may be lost in the coming years and, possibly, permanently reduce the usefulness of the data were added to the CD-ROM. Various paper items such as cruise reports, data processing records (historically referred to as green sheets), data format descriptions, data processing program descriptions and generated data summary reports not previously available were included. It is hoped that the R/V FAY data CD-ROM is viewed as a "neat pile" of data (neat as tidy; clean; not mixed with anything) providing a complete background of the cruises and data.
If the data were currently unused, why save them?
Well that point may be debatable and perhaps better rephrased as why invest more time and money on unused data. As mentioned above, the selected tapes transcribed to this CD-ROM had become under-utilized during recent years. It is believed that, though the data had not been heavily accessed in recent years, they represented historical data for future studies, and uses such as having available the navigation data to complement the collected seismic data were significant enough to warrant the undertaking of the data rescue project. Additionally, these data were originally collected at significant cost and the decision was made to invest a significantly smaller amount of time and money in an attempt to save the data.
If the data are so important, then why not save all the tapes?
Approximately thirty-five percent of the R/V FAY tapes were transcribed from their 9-track medium to an individual ASCII file on this CD-ROM. Those tapes include the (unedited or unprocessed data extracted from the field acquisition tapes), some intermediate and edited data files that were archived, and the final, processed versions of the collected and archived navigation and geophysical data.
Unfortunately, not all the R/V FAY tapes could be transcribed to the CD-ROM. One major set of tapes that could not be transcribed were field acquisition tapes collected in the Dead-Reckoning-Data (DRD) format. These DRD tapes account for the majority of the missing sixty percent of the R/V FAY tapes not transcribed to this CD-ROM and are the tapes from which most of the data mentioned above were originally extracted. Data recorded in the DRD format were on 800 BPI tapes but recorded in a system specific binary format. Attempts to read these tapes proved fruitless and were abandoned. It is believed that any field acquired data that may be desired are available in one of the transcribed data formats available on the CD-ROM and should not be considered lost.
Similar to the DRD formatted tapes, the Time-Series Data (TSD) formatted tapes were not transcribed to the CD-ROM. The TSD series tapes were generally a conversion of the DRD formatted tapes to allow in-house interactive editing of the navigation data contained on the DRD data and necessary for the processing of the geophysical data. The TSD formatted tapes also proved impossible to transcribe to the CD-ROM. Data tapes in this format and plans to include this data set were also eliminated.
The decision was made to continue to have the DRD and TSD formatted tapes remain in the data library for now.
A few other miscellaneous tapes that were identified in the data library as FAY tapes were not transcribed. These included tapes such as those formatted in binary and for plotting with software no longer available to Center members and data regurgitated into yet another format that cannot be accurately documented.
How were the tapes transcribed?
A 486/66MHz IBM compatible PC was purchased to serve as the central workstation to support the data rescue project. A Qualstar 3412S 9-track magnetic tape drive was purchased and attached to the 486 computer system via an Adaptec 1542 SCSI-2 controller. The Qualstar tape drive provided the necessary support to read the 800 and 1600-BPI tapes and included a simple menu driven DOS program for transferring the text files from tapes to disk. Finally, a 1.0 Gbyte disk drive with a low density (2.35 Gbyte) 8mm Exabyte tape drive was added to the workstation to provide the necessary workspace for developing the CD-ROM.
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