schema translation – os mastermap, but not as we know it eddie curtis, snowflake software, greg...
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Schema Translation – OS Mastermap, but not as we know it
Eddie Curtis, Snowflake Software,
Greg Byrom, Richie Fyall
GeoData Management Group
Ordnance Survey
22nd September 2005
Schema Translation – project objectives
Objectives of the Schema Translation project were:
• Prove the concept of schema translation using OS MasterMap as the source
• Investigate technical feasibility & constraints of using XML translation software for this purpose
• Understand implications of presenting Ordnance Survey data using different target schemas
• Understanding implications for internal Ordnance Survey data management
Target schemas chosen
• EuroRoads would be first choice, but no schema available.
• KML: Keyhole Markup Language for Google Earth. (Not GML)
• Simple Features GML:
• We created a simplified GML schema for both topographic and transport/routing data.
• GOS-TP (Geospatial One Stop - Transportation Pilot): Transport network schema.
• OKSTRA: Transport network schema for German road network.
Translating OS Mastermap GML
GO Publisher Desktop
Data Store
SchemaTranslation
Schema Translation
WFS Client
WFS Client
SQL Query
SQL Query
Database Records
Database Records
GML
GML
Data Request
Data Request
Translation Configuration
Database table information
Graphical user interface is used to defined the translation from the storage model to the XML data model.
Translations are uploaded to the server.
GO Publisher can publish the same data in different XML formats for different clients.
ITN to OKSTRA translation
ITN Model Semantic Mapping
GO Publisher
OKSTRA model
Oracle Records
OKSTRA GML file
Rel
atio
nal
Impl
emen
tatio
n
XM
L Im
plem
enta
tion
ITN Relational Schema
GO Publisher ProjectOKSTRA
GML Schema
Conclusions
To do schema translation:
• Understanding of XML schemas is a necessity. Ability to analyse target schemas and decide which fields to match.
• Schema documentation is a necessity. OS Mastermap schema very well documented, others vary.
• Many XML schemas are still in research or development phases, especially market sector specific schemas.
• Only semantically similar XML schemas can be used as target schemas.
• Schema Translation is a flexible, useful tool for Ordnance Survey to produce data tailored to market requirements.
Contact for further information
Customer Contact CentreOrdnance SurveyRomsey RoadSOUTHAMPTONUnited KingdomSO16 4GU
Phone: 08456 05 05 05
Fax: 023 8079 2615
Email: [email protected]
Web site: www.ordnancesurvey.co.uk
Eddie Curtis
CTO
Snowflake Software
Tel: +44 23 80386571
www.snowflakesoftware.co.uk
Questions ?
Eddie Curtis
CTO
Snowflake Software
Tel: +44 23 80386571
www.snowflakesoftware.co.uk