Chromatogram Standardization, Inventory, and Storage Renewal
Complications. The saving of chromatograms took far more time than anticipated due to a variety of complications. The number of file naming and storage conventions that resulted over the years from changes in RITS system hardware and software was a significant factor. More important by far were the difficulties encountered with the primary storage media, the magneto optical disk, which suffered throughout much of the year 1993 from an attenuated laser. As a result, a very high number of read errors occurred while retrieving chromatograms from the disk storing the data recorded that year. Several repairs were made to the disk's filesystem before it became irrevocably corrupted. This forced the retrieval of chromatograms from the secondary storage media, DC600 tape. The recovery was painstakingly slow by comparison and exacerbated by fact that these backups were made from fresh data floppies shortly after their arrival in Boulder and prior to any efforts made at quality control. Much additional programming was required to cross-check these chromatograms with the areas/heights database in search of sections where sample-type labeling and timestamp corrections had formerly been applied. Furthermore, it was discoverd that a week's worth of data contained on a floppy disk from Mauna Loa had been overlooked during tape backup. These chromatograms were rescued by performing a block-by-block extraction and reassembly of the files stored on the corrupted optical disk. Since each chromatogram contains an internal timestamp and channel identifier but no internal station identifier, all reassembled files within the lost time period were given filenames with a bogus station identifier. These were then compared with the chromatograms for the other three stations that were retrieved from tape (there were no South Pole chromatograms from the year 1993). Those for which no match was found were assumed to be the missing chromatograms from Mauna Loa. Confirmation of this assumption was given by a visual inspection of the plotted chromatograms.