The following is a guest post by Chelcie Rowell, 2012 Junior Fellow.
A recent behind-the-scenes tour of the Packard Campus of the Library of Congress in Culpeper, VA, offered us Junior Fellows a glimpse into the cutting edge of audiovisual preservation, as well as insight into incremental development of a digital preservation effort.
Undoubtedly one of the coolest things we saw on our tour was the robot IRENE (short for Image, Reconstruct, Erase Noise, Etc.) which was designed at the intersection between particle physics and digital preservation. A collaboration between the Library of Congress and the Lawrence Berkeley National Laboratories, IRENE is one solution to a difficult audiovisual preservation problem.
The problem: As the IRENE website at LBL indicates, many analog formats for recorded sound risk data loss each time a recording is played, from a stylus that could damage a vinyl record to tape players that could stretch or abrade tape. For recordings on these formats, access is in direct conflict with preservation. Migration to a digital format helps to resolve this conflict. While migration from analog format to analog format produces a decrease in quality with each generation of migration, once the recording is migrated to a digital format the quality of the initial capture can be maintained throughout successive migrations. However, even migration to digital format requires playing the recording—and sometimes accepting a concomitant loss of data. The problem faced by sound preservationists was how to migrate to a digital format without degrading sound quality during migration.
A solution: Rather than playing a recording in order to migrate it to a digital format, IRENE captures high-resolution 2-D images of the grooves in a disk record without tactile contact. Software can then retouch the map of the record’s surface to erase noise caused by damage to the physical record, and “play” the record with a “virtual needle.” After testing by the Library’s Preservation Research and Testing division, IRENE is now being put to work in Culpeper to migrate sound recordings from an analog to digital format—without causing damage at the point of migration and even mitigating damage caused by existing oxidation, warping or dirt. A cousin to IRENE that uses 3-D imaging to capture sound from vertical grooves in wax cylinders is still in development.
Admittedly high-tech, IRENE has something to say about incremental development of any digital preservation effort: define the problem and, starting with the tools you have, iterate solutions. As a graduate assistant at a large academic library, my crash course to preserving born-digital materials followed a similar pattern.
The project I worked on was an effort to preserve born-digital materials related to a major campus construction project by transferring documents from two active servers—a shared network server as well as a project-management wiki stored on a web server—to a preservation server. Although my institution had worked with born-digital materials before, those materials had been received (already aggregated) on external hard drives. A workflow for server-to-server accessions had not yet been developed.
Fortunately, the wiki was used primarily as a table of contents for documents, so our preservation efforts did not extend to web archiving; instead, our purpose was to preserve documents linked to on the wiki and stored on a web server. Still, developing this new workflow presented three major challenges:
- To aggregate materials related to the construction project (neither source server was devoted wholly to construction planning) within directories that represented design phases of the construction project.
- Within each directory related to a design phase, to preserve the “original order” of the wiki even though its materials were stored on a web server using a directory structure randomly assigned by wiki software.
- To de-duplicate materials within and across the two source servers before transfer.
Our solution used a combination of free and open-source command line tools to transfer files and perform authenticity checks. Broadly brushed, our workflow was to inventory files related to the construction project on each active server, create the desired directory structure on a local machine, transfer files from each active server to the local desktop, and finally transfer the files from the local desktop to a preservation server. Authenticity checks were performed before transfer (to aid in de-duping) and after transfer (to verify integrity).
Having been successfully transferred to a preliminary accession folder on a preservation server, the materials could await further arrangement and description by an archivist more safely than if they had remained scattered on active servers where space was at a premium and the risk of intentional or unintentional deletion was very real.
Other preservation actions would certainly be necessary for the long-term stewardship of these materials, such as assigning unique identifiers and creating metadata, but we made sure to document this first effort well so that the workflow could be refined, generalized, and scaled for other server-to-server accessions.
Corrected typo, 6/13