1. Combining OS and OSM Data - A Case Study for geospatial data integration Name: Du Heshan Supervisor: Dr Suchith Anand

2. Presentation Outline Project Background Project Objective A Case Study: OS vs OSM Methodology Software Demo Current Work and Future Plan

3. Project Background - Geospatial data integration Geospatial data integration (GDI) is the merging of geographic data, including spatial and non-spatial data, from disparate sources with differing conceptual, contextual and typographical representations.

4. Project Background -Initiative for GDI >80% information has a spatial component Sources of geographic information –Different levels GEOSS (Global), INSPIRE (Europe), Ordnance Survey (National) –Different countries –Different approaches, styles: OS (Authoritative) vs OpenStreetMap (Crowdsourced) Communication, collabration, improvement

5. Project Background -Open Source GIS Rapid growth of open source GIS Based on open source standards –OGC, ISO TC 211 Advantages –Open access to source code –Low cost, free

6. Project Objective Combining OS and OSM datasets as a case study for GDI Developing software applications based on Open Source framework to automate the process

7. A Case Study -Ordnance Survey and OpenStreetMap source aspectOrdnance SurveyOpenStreetMap Data Collection Top-down, formal, expensive Bottom-up, informal, low cost Authority HighLow Accuracy HighLow InformationStructuredRich, flexible tag

8. A Case Study -Ordnance Survey and OpenStreetMap * OS-ITN portsmouth * OSM Road

9. Methodology First Step: How do we define data from different sources are corresponding, refering to the same object? Geometric matching Ontology matching Second Step: Semantic integration

10. Geometric Matching Geometric accuracy of data differs Background previous work of interest: –Ather, a quality analysis of OpenStreetMap Data –Al-Bakri and Fairbairn, assessing the accuracy of crowdsourced data and its integration with official spatial data sets. –Lianxia Xi, map matching algorithm and its application Buffer Analysis and Map matching Suffer from segmentation problem

11. Geometric Matching -Segmentation Problem * OS-ITN * OSM

12. Ontology Matching Heterogeneous databases –Independent development –Own data vocabulary –May conflict in structure, context, and value Ontology: –Nature and categories of being, their relations Semantic correspondences

13. Ontology Matching - similar fields dataset fieldsOS-ITNOSM road nameROADNAMEname road typeDESCRIPT1highway

14. Ontology Matching -Road Network Build up network, especially for OSM Rely on relationships to identify a road Matching road by road

15. Semantic Integration Interrrelating information Study metadata, product specification Design a new data model –First step: adding OSM field to OS data

16. Software Demo * Simple GDI tool * Network building

17. Ongoing Work and Future Plan Ongoing work: –Literature review, open source GIS software development Future Plan: –For the case study: More ontology matching Combine geometric and ontology matching, algorithm optimization Design a integrated data model –Generalize the methodology for GDI

18. Thank you !