ISSN 1039-3498 | no. 56 | April 2002
Developing Digital Services Architecture
During the past four years the National Library of Australia has been developing, through its Digital Services Project, an overall architecture for its digital collection management. This architecture, embracing both digitised and born-digital information resources, was described in the Digital Services Project Information Paper published by the Library in December 1998 at www.nla.gov.au/dsp/infopaper.html.
The main components of this architecture are:
The Digital Object Storage System which meets the Librarys needs for the large-scale storage of digital collection items.
The Digital Archiving System which provides Library staff with the tools to manage the gathering of selected Australian web sites and electronic publications, their long-term storage and the provision of access by the public.
The Digital Collections Manager which will provide support for management of the Librarys special collections (maps, manuscripts, pictures, printed music, sound) including support for the digitisation process, ongoing format migration and preservation processes, and the recording of intellectual property rights information.
A Metadata Repository and Search System to provide Resource Discovery services.
A Persistent Identifier Resolver Service so that all digital collection objects can be allocated a Persistent Identifier and can be accessed via the Internet using this identifier.
Delivery Systems for complex digitised collection items such as Manuscripts, Maps, Sheet Music and Audio recordings.
This article sets out the progress which the Library has made in developing this architecture.
Digital Object Storage System
This system became operational in July 2001, providing an initial online capacity of two Terabytes and a nearline capacity of four Terabytes. (Nearline means that the data is delivered with a short delay, typically less than 10 minutes). As of March 2002, over one Terabyte of digital collection material has been stored in the system. This includes material from the PANDORA Archive, digitised map, manuscript, sheet music and pictorial images, and oral history audio files.
| Collection |
Images |
Total Size
(GB) |
Average Size
(MG) |
| Maps |
143 |
22
|
158 |
| Manuscripts |
5506 |
31 |
24 |
| Sheet Music |
5201 |
177 |
35 |
| Pictorial |
3046 |
63 |
21 |
The Library recently commissioned new digital audio workstations which allow Oral History material to be stored on the Digital Object Storage System. This material requires approximately 20 times the storage space of a typical digital image file. To support this rapid increase in storage needs, the Library is planning to add a further eight Terabytes to the capacity of the Digital Object Storage System later in 2002.
Digital Archiving System
The Digital Archiving System, PANDAS, (formerly called the PANDORA Collecting System) was implemented in July 2001. This software was developed in-house by the Library after a Request for Tender in late 1999 failed to identify any suitable solutions in the marketplace. A number of State libraries, and ScreenSound Australia, are also using this system to contribute to the PANDORA Archive. A new release of the system (Version 2) is now under development, and is scheduled to be completed in June 2002. This release will further improve workflow efficiencies for collection staff and also allow archived material to be distributed nationally rather than held centrally at the National Library.
Digital Collections Manager
The Digital Collections Manager is being developed in-house by the Library after a Request for Quotation issued during 2000 failed to identify a sufficiently affordable and low-risk solution in the marketplace. The first release of this software will support the digitisation of pictures, maps, manuscripts and sheet music. The initial release of this software (Version 1.0) was undergoing its final testing in early March. This release will support the Librarys digitisation workflows and allow digitised images to be uploaded to the Digital Object Storage System.
In future releases the Digital Collections Manager will be enhanced to support:
Metadata Repository and Search System
The Librarys requirements for resource discovery services are met by its catalogue and by the Metastar Enterprise server product, which was licensed from Blue Angel Technologies in 1999. The Library has developed a number of resource discovery services using Metastar Enterprise, including PictureAustralia, OzLife (an index to biographical and book review articles in newspapers and journals) and Australian Journals Online.
The most recent service to use this product is the new Pictures Catalogue, released in October 2001. The Pictures Catalogue provides a single point of entry to the Librarys Pictorial Collection, and enables the Library to offer a digitisation-on-demand service for material in the collection that has not yet been digitised.
The Library is now reviewing the future of its resource discovery services, with particular reference to the Librarys needs for online performance in searching large metadata sets such as PictureAustralia.
Persistent Identifier Resolver Service
In August 2001 the Library implemented an online resolver service for its digital collection items. This service accepts web requests which refer to a digital collection item by its permanent identifier, and redirects them to the current storage location of that item. The service was implemented following the recommendations of a consultancy on Persistent Identifier Systems found at www.nla.gov.au/initiatives/persistence/PIcontents.html.
Persistent Identifiers and the resolver service provide a reliable and stable way of naming items from the collection. These identifiers can be used in citations (both online and in print publications) knowing they will persist long into the future, irrespective of changes to the delivery mechanisms. Persistent Identifiers are included at the bottom of every image (except thumbnails) delivered by the librarys digital services.
Delivery Systems for
Digital Objects
During 2001 the Library developed
a delivery system for manuscript collections. Access to the collection items is
managed by the finding aids developed for these collections using a standard
known as EAD (Encoded Archival Description). The first manuscript collection to
be delivered using this framework was the papers of Sir Edmund Barton (see
Gateways no. 54, December 2001).
The Library is currently developing a delivery system for digitised sheet music. This system, which will use the technology developed for manuscripts, is scheduled for implementation in June 2002.
Early in 2002 the Library embarked on a pilot project looking at the technologies and functional issues involved in the web delivery of audio from the oral history and music collections.
Conclusion
The Library has
adopted an architecture for the management of its digital collections which
embraces all of the key library processes of selection, acquisition, storage,
resource discovery, delivery, access control and preservation. Many of the
components of this architecture have been implemented or are under active
development.
Warwick Cathro
| Contents list for this issue of Gateways |
Please address any comments and enquiries to The Editor, Gateways: dthomas@nla.gov.au