Preservation Strategies in the North Carolina Geospatial Data Archiving Project (NCGDAP) NCSU Libraries Steve Morris Head of Digital Library Initiatives

Preservation Strategies in the North Carolina Geospatial Data Archiving Project (NCGDAP)

NCSU Libraries

Steve Morris Head of Digital Library Initiatives

Digital Preservation in State Government: Best Practices Exchange 2006

Note: Percentages based on the actual number of respondents to each question 2

Overview

Digital geospatial data preservation issuesTechnical solutionsOrganizational/cultural solutions


NC Geospatial Data Archiving Project

Partnership between university library (NCSU) and state agency (NCCGIA), with Library of Congress under the National Digital Information Infrastructure and Preservation Program (NDIIPP)One of 8 initial NDIIPP partnerships (only state project)Focus on state and local geospatial content in North Carolina (state demonstration)Tied to NC OneMap initiative, which provides for seamless access to data, metadata, and inventoriesObjective: engage existing state/federal geospatial data infrastructures in preservation


Targeted Content

Resource TypesGIS “vector” dataDigital orthophotography Digital mapsTabular data

Content ProducersMostly state, local, regionalSome university, commercialSelected local federal projects


Today’s geospatial data as tomorrow’s cultural heritage

Future uses of data are difficult to anticipate (as with Sanborn Maps).


Risks to Digital Geospatial DataProducer focus on current data

Time-versioned content generally not archivesFuture support of data formats in question

Vast range of data formats in use--complexShift to “streaming data” for access

Archives have been a by-product of providing accessPreservation metadata requirements

Descriptive, administrative, technical, DRMGeodatabases

Complex functionality


Different Ways to Approach Preservation

Technical solutions: How do we preserve acquired content over the long term?

Cultural/Organizational solutions: How do we make the data more preservable—and more prone to be preserved—at point of production?


Vector Data Format OptionsOption A: use an open format and have a really unfortunate transformation and limited vendor support for the output objectOption B: use closed format but retain the original content and count on short- and medium-term vendor support. Option C: do both to buy time and look for an open, ASCII solution. (watch GML activity)

No sweet spot, just an evolving and changing mix offlawed options that are used in combination.


Preserving Cartographic Representation

Counterpart to the map is not just the dataset but also models, symbolization, classification, annotation, etc.


Preserving GeodatabasesSpatial databases in general vs. ESRI Geodatabase “format”Not just data layers and attributes—also topology, annotation, relationships, behaviorsGrowing use of geodatabases by municipal, county agenciesSome looking to Geodatabase as archive platform (in addition to feature class export)ESRI Geodatabase archiving approaches

Feature Class Export, XML Export, Geodatabase History, File Geodatabase, Geodatabase Replication


Harnessing Geospatial Web Services

Image atlases from WMS services?Capturing cartographic representation?Recording records from decisions-making processes?Later: data transfer via WFS & GML?, Other?


Interest in how geospatial content interacts with widely available digital repository softwareFocus on salient, domain-specific issuesChallenge: remain repository agnostic

Avoid “imprinting” on repository software environmentPreservation package should not be the same as the ingest object of the first environmentTension between exploiting repository software features vs. becoming software dependent

Project Repository Approach


Organizational/Cultural Approaches

Take the dataas is, in the manner in whichit can be obtained

Provide feedback to producer organizations/inform state geospatial infrastructure

“Wrangle”and archivedata

Note the ‘Project’ in ‘North Carolina Geospatial Data ArchivingProject’– the process, the learning experience, and the engagementwith industry and infrastructure are more important than the archive


Framework data communitiesSnapshot frequency, naming schemes, classification, GML application schemas, format strategies

Metadata standards and outreachPersistent identifiers, versioning, feedback on metadata quality

Content replication/transferFor data improvement projects, disaster preparedness, aggregation by regional service providers, … and archives

Where does archiving and preservation fit in?

Points of Engagement with Spatial Data Infrastructure


Geography Markup Language (GML) for archiving (PDF/A version of GML?)GeoDRM

Adding preservation use casesContent Packaging

Will there be an industry solution?Web Map Context Documents

Can we save data state as well as application state?Content Replication

Is this a layer in the overall architecture?Persistent Identifiers

Points of Engagement with the Open Geospatial Consortium (OGC)


Software vendorsBetter support for temporal data managementTools for retrospective data conversion

Web mashup and open source communitiesWMS caching schemesStandard tiling schemes with temporal component?

Data vendorsCultivate market for older data (scaled pricing?)Tech transfer on archiving practices?

Points of Engagement with Industry


Project StatusCultivating a market

for older data.


Project StatusCultivating tools for

retrospective conversion.


Geospatial data is complex, introducing manifold challenges to ingest processes and repository developmentVector data and spatial databases are especially complexGeospatial data exists in very large quantities and is subject to frequent updateNeed to engage industry in the solutionNeed to engage point of production

Conclusion


Questions?

Contact:

Steve MorrisHead, Digital Library InitiativesNCSU [email protected]

Web site: http://www.lib.ncsu.edu/ncgdap/