Alexandria Digital Earth ProtoType Architectural Directions for Distributed Geolibraries Greg Janée

Alexandria Digital Earth ProtoType 2 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 Outline o (Previous) testbed design and experiences o Vision & goals o Architecture: foundation  CRADDL  FEDORA o Architecture: additions  Standard thesaurus interface  Two standard metadata models  Core index/search service  Tile-based browse/aggregation service  Collection discovery service  Gazetteer service o Goals, revisited

Alexandria Digital Earth ProtoType 3 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 Testbed: Concepts o a distributed catalog system  Library –set of collections –client (public) services  Collection –set of holdings –metadata reports –library (internal) services  Holding –unique identifier o Holdings have footprints  Earth surface location(s) –point –bounding box –polygon(s)  Gazetteer converts names  footprints o Services accessible via HTTP  Methods = URLs o Metadata encoded in XML  Queries  Reports

Alexandria Digital Earth ProtoType 4 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 Testbed: Metadata o “Search Buckets” (generic query metadata)  Geographic locations  Dates  Types  Formats  Originators  Subject-related text –Assigned terms  Identifiers o Reports (descriptive metadata)  Collection  Scan  Full  Browse  Access

Alexandria Digital Earth ProtoType 5 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 Testbed: Services Clients  Configuration {collection-id}  Collection(collection-id) report  Query(query) query-id  Results(query-id) {holding-id}  Metadata(collection-id, holding-id, view) report Libraries  Collection report  Query(query, accumulator) query-thread  Metadata(holding-id, view) report Collections

Alexandria Digital Earth ProtoType 6 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 Testbed: Implementation webclient intermediary ADL middleware server collection driver web browser Java + XML servlet engineJDBC collection metadata (complete) HTTP + HTML renderer (offline) coverage/statistics scripts collection metadata (static) XML HTML + GIF map/footprint service HTTP server HTTP + GIF map server vector map data local file cache Berkeley/DBM databases (multiple per series) collection database indexed search buckets + basic holding metadata HTTP server metadata accessors (one per series) data accessors (one per series) XML RDBMS HTTP + XML HTTP SRB to SDSC collection middleware client Java + XML configuration scripts

Alexandria Digital Earth ProtoType 7 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 Testbed: CDL Web Client

Alexandria Digital Earth ProtoType 8 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 Testbed: Contents Series# ItemsSize (GB) Geodex map index322,000- Landsat1,514,000- DOQQ10, DRG 1:24,0003,00066 DRG 1:100, NASA air photos502,000- MIL air photos15, SPOT2006 DEM3,0001 ADL Gazetteer4,000,000- UCSB AVHRR15, TOTAL6,385,4501,879

Alexandria Digital Earth ProtoType 9 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 Vision o Fundamental organization of information  Self-contained, georeferenced digital objects... ...aggregated into collections... ...networked into libraries  The Library constitutes a “Digital Earth” o Static and dynamic content o Personal, customizable collections o Collaborative use of distributed resources o Component-based approach  Specify interfaces and protocols  Build representative services

Alexandria Digital Earth ProtoType 1010 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 Goals o Find  Find appropriate collections  Find items within collections –Using simplified, uniform methods –Using more refined, perhaps collection-specific methods o Assemble, structure, publish  Create and populate new collections  Structure collections using domain-specific thesauri  Make available to others o Use  Invoke operations on items  Integrate library into user application environment

Alexandria Digital Earth ProtoType 1 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 CRADDL D-Lib Magazine, Nov client index/search naming repository update index submit query; retrieve results retrieve, deposit, and operate on digital objects resolve name collection get configuration, characteristics update summary information

Alexandria Digital Earth ProtoType 1212 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, identifier FEDORA crop(x,y,w,h) subsample(factor) getThumbnail() type “image” implementation “image” apologies to Christophe Blanchi Type signature implementation attachments crop(x,y,w,h) subsample(factor) getThumbnail()

Alexandria Digital Earth ProtoType 1313 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 Architecture: additions o Standard thesaurus interface o Two standard metadata models  ADL-Basic: supports uniform description & search  ADL-Full: supports XML-based querying on entire metadata o Standard index/search services  Core index/search service  Tile-based browse/aggregation service o Collection metadata  Characterizes collection  Supports collection discovery o Gazetteer service

Alexandria Digital Earth ProtoType 1414 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 getTopTerms() getDefinition(term) getBroaderTerm(term) etc. getNarrowerTerms(term) Standard thesaurus interface ridge A long and narrow upland with steep sides. physiographic feature mountain drumlin cliff summit arête hogback broader narrower relatedpreferred broader narrower broader narrower

Alexandria Digital Earth ProtoType 1515 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 ADL-Basic fields & subfields o Originator o Subject-related text  Title  Assigned terms o Type o Format o Spatial domain o Date  Time period of content o Identifier

Alexandria Digital Earth ProtoType 1616 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 FGDC DOQ 3.11 FGDC 1.1/8.2 Semantics Source image date Source DEM date Production date Name Repeatable Optional Always present Characteristics DATE collection metadata ADL-Basic general structure FGDC DOQ 3.11 FGDC 1.1/8.2 Semantics Source image date Source DEM date Production date Name Value DATE digital object clientindex/search service

Alexandria Digital Earth ProtoType 1717 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 ADL-Basic field definition o Semantics identifies the nature, genre, meaning, or intellectual content of the item o Content zero or more terms drawn from identified thesauri o XML representation o Collection metadata implications collection metadata lists all referenced thesauri o Query value single term from an identified thesaurus o Query operator “ is a” {(“Object Types”, “aerial photograph”), (“Geology Concepts”, “erosion”)} Type is a (“Object Types”, “image”) Type

Alexandria Digital Earth ProtoType 1818 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 ADL-Full o Encodes the full, native metadata in a standard syntactic representation  RDF  ADL’s generic encoding

Alexandria Digital Earth ProtoType 1919 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 Index/search services o Core index/search service  Based on ADL-Basic  Boolean combinations of constraints on ADL-Basic fields and subfields (only) o Support for other, more refined search services  Utilizing ADL-Basic metadata mappings  Based on ADL-Full

Alexandria Digital Earth ProtoType 2020 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 Browse/aggregation service  Aggregate statistics  Digital objects (scale-dependent)  By type, format, and date

Alexandria Digital Earth ProtoType 2121 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 Collection metadata o Static  Scope and purpose, maintaining agency, etc. o Derived  Referenced thesauri  Referenced metadata standards  Native  ADL-Basic metadata mappings o Statistical summarization via browse/aggregation service

Alexandria Digital Earth ProtoType 2 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 o Stratford-upon-Avon  Variant namesStratford upon Avon; Stratford  LocationN 52° 11’, W 1° 42’  Feature typepopulated place (NIMA); town (local)  Time period1196–present o 805  Feature typeU.S. telephone area code o 37T  Feature typeUTM zone o Mississippi  Feature typedrainage basin Gazetteer service (1/3)

Alexandria Digital Earth ProtoType 2323 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 postal codes 2 nd order administrative areas 1 st order administrative areas Gazetteer service (2/3) o Geographic namespace: spatial partition of a region into uniquely named subregions countries time zones U.S.A. U.K. states counties ZIP codes postal codes national parks continental plates California Louisiana parishes counties

Alexandria Digital Earth ProtoType 2424 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 map service client Gazetteer service (3/3) browse/aggregation service gazetteer placenames Yogi Cabbage Patch Pancake Bamm-Bamm Barnacle Bill Wedge

Alexandria Digital Earth ProtoType 2525 Greg Janée  JISC/CNI  Stratford-upon-Avon  June 14, 2000 Goals, revisited o Find  Discovery service based on rich collection metadata  Uniform searching based on ADL-Basic  More refined searching based on ADL-Basic and ADL-Full  Browse/aggregation service o Assemble, structure, publish  Uniform use of collections  Thesauri and inheritance of collections and digital objects support customization & structure  Collections designed to span gamut big  small o Use  FEDORA-like extensible digital object model