Report on Progress. Overview First cut gazetteer database built Basic working demonstrator built...
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Transcript of Report on Progress. Overview First cut gazetteer database built Basic working demonstrator built...
Report on Progress
Overview
• First cut gazetteer database built
• Basic working demonstrator built– simple interface for reference use
– basic machine2machine protocols adopted
• Servicing Go-Geo!
• Adaptation of ADL Feature Type Thesaurus (see separate handout)
• Outreach and stakeholder engagement underway
geoXwalk - High Level Architecture
The geoXwalkServer
(Spatially enabled RDBMs)
Web client
Request via protocol(ADL, OGC, Z39.50)
Information server
Request via protocol(ADL, OGC, Z39.50)
(human interaction)(machine2machine interaction)
Gazetteer Database
• Built on ADL Content Standard
• Currently seeded with:– OS 1:50,000 digital Gazetteer
– digital boundary data from UKBORDERS
– data sourced from other OS products - Strategi, Meridian, 1:250,000 gazetteer
– starting to add 3rd party data including Getty
• Accuracy enhanced and metadata support
• Current coverage:– Geographical - GB
– Thematic - see below
ADL Gazetteer Content Standard
Geographic Feature ID Geographic Name Variant Geographic Name (R) Type of Geographic Feature (R) Other Classification Terms (R) Geographic Feature Code (R) Spatial Location (R) Street Address Related Feature (R) Description Geographic Feature Data (R) Link to Related Source of Information (R) Supplemental Note
Metadata Information
http://www.alexandria.ucsb.edu/gazetteer
• comprehensive description but with small set of core elements• temporal aspects of names, footprints, relationships, …• documents source, spatial accuracy/scale of footprint• does permit explicit relationship types!
Feature Typing• need to incorporate a
dictionary of allowed terms which defines each feature type
• typing supports queries such as – “What schools exist in Leeds and
where are they?”
– Show lakes in Cornwall
• hierarchy of feature types preferred
• propose to adopt the ADL Feature Type Thesaurus
• some problems… but ADL acknowledges these
• adapted thesaurus for UK
hydrographic features
. aquifers
. bays
. . fjords
. channels
. deltas
. drainage basins
. estuaries
. floodplains
. streams
. . rivers
. . . bends (river)
. . . rapids
. . . waterfalls
geoXwalk gazetteer - current thematic content
(based on adapted ADL Feature Type Thesaurus)
Reference use
Information server
Information server
Searching
Geo-parsing &indexing
The geoXwalkServer
geoXwalk as digital gazetteer service: use
cases
Supporting reference: the “where is?” type
of question
What is at grid ref. NY 305 573 ?
Where is Aberdour?
What is the largest town in Nottinghamshire?
List me all places ending with ‘kirk’
What parishes fall within the Lake District National Park?
On what river is Dundee situated?
Which Roman roads pass through Scotland?
By what alternative names has York been known?
+ research use to resolve variant names etc.
Demonstration
Task: Find resource about 'Liverpool docks’Search using a ‘traditional’ gazetteer might yield:
Using spatial proximity in an active gazetteer, the search can be widened:
Place County/UALiverpool Liverpool
Bebbington Wirral
Birkenhead Wirral
Bootle Sefton
New Brighton Wirral
Seacombe Wirral
Seaforth Wirral
Waterloo Sefton… that means more & better hits …. !!!
co-ordinates allow (near) co-located places to be co-identified.
Demonstration
Supporting cross searching different services
geoXwalkServer
Content Provider C
ContentProvider A
ContentProvider B
Co-ordinate footprints
Parish names
Place names
Portal service
Post code: L34 0HS?
‘Find resources for this postcode’ (NB postcode often used to geo-reference survey data files)
Knowsley
340900,392300 - 347217, 397660
BX003
Demonstration(Go-Geo!)
Protocols
• Why adopt a protocol at all?– agreed set of rules and interfaces (limit proliferation)
• ADL Query Protocol– lightweight, generic, relatively simple to implement
• OGC Filter Encoding Specification– fuller, highly flexible, more complex
• Z39.50– pervasive in JISC IE, not specifically for geo-spatial
data, lack of support
• identifier-query identifier Return gazetteer entry identified by identifierSupported by geoXwalk
• name-query operator text Returns gazetteer entries which match text under text-operator operator geoXwalk supports the mandatory equals operator and the optional match-pattern operator
• footprint-query operator (polygon | box | identifier)Returns all gazetteer entries having a footprint that matches a query region according to spatial operator operatorgeoXwalk supports spatial operators within, contains and overlaps. Spatial extents can be specified by bounding box or identifier.
5 types of ADL query:
ADL queries (contd)
• class-query thesaurus term Returns all gazetteer entries which belong to the class (feature type).geoXwalk supports class queries (but currently does not return sub-classes by default as the ADL does)
• relationship-query relationship identifier Returns all gazetteer entries having relationship relationship to a target gazetteer entry identified by identifier.geoXwalk does not support queries of this type because we do not hold explicit relationships between entities - they are derived implicitly from the geometries
Demonstrationm2m
Outreach and evaluation
• JISCmail list established
• leaflet produced
• project web pages available
• discussions with various stakeholders
• discussions with data providers
• report and outcomes of this meeting will be written up