Heterogeneous Geographic Objects Interoperability Victor Azevedo Master Student in Geomatics/UERJ Geoinfo, 2006 Margareth Meirelles Rodrigo Ferraz Antônio Ramalho Filho

Summary Motivation and Goals Some Concepts Methodology Case Study Results Conclusions and Future Works

Motivation Biofuel government program; Agro-Ecological Palm Oil Zoning in Legal Amazon deforested areas (MCT - Embrapa); Exchange soil geographic data among heterogeneous geographic data sources (SIPAM, IBGE, EMBRAPA and others)

Possible Contributions Inherits geographic data from different institutions; Data acquisition represents 60% - 80% of GIS implementation cost [Hartman 1998]; Geographic Data Consortium; Use distributed environment (internet) to exchange geographic data. = Exchange information among different geographic data producers;

Goals Propose a methodology to provide the interoperability among heterogeneous and distributed geographic objects (features) considering the syntactical, semantic and data format integration aspects; Contribute to the development of researches in spatial data integration

Specific Goals Propose an automatic integration of distributed heterogeneous geographic objects, based on: Open Geospatial Consortium (OGC) Specifications of Geographic Markup Language (GML) and Web Feature Services (WFS) plus domain ontology in Ontology Web Language (OWL) and metadata structure

Specific Goals Model the expert soil knowledge based on ontology sharing the results in OWL format. Develop a prototype to integrate two soil geographic data sources providing the result in a known geographic format; Apply the methodology to the project: Agro-Ecological Palm Oil Zoning in deforested areas of Legal Amazon (data from Embrapa Solos, IBGE, SIPAM and others institutes).

Summary Motivation and Goals Some Concepts Methodology Case Study Results Conclusions and Future Works

GIS Interoperability Heterogeneous Formats Shapefile GML DGN PostGIS TIFFGeoTIFF DXFMIF Oracle Spatial DLG MySQL MrSID ArcSDE

GIS Interoperability

How to make GIS Interoperability? Solving incompatibilities in three levels [Casanova et al 2005]: Formats Syntax Semantics Standardization

Summary Motivation and Goals Conceptualization Methodology Case Study Results Conclusions and Future Works

Methodology Geographic Object Servers (GOS) definition; –Provide Geographic Data in GML using a WFS Server. Integration Server(s) (GeoIS) definition; –Register each GOS; –Register Domains and Ontologies; –Correlates domain terms with GOS terms; –Generate the integrated version of Feature Collection. Service Oriented Architecture (SOA) Definition

Methodology For each geographic data source, publish the geographic objects in GML using a WFS Server; Some GIS and Map Servers implement the OGC WFS specification; –Geoserver, MapServer, MapGuide, ArcIMS, etc… Service Oriented Architecture (SOA) Definition Provide Geographic Objects in GML with WFS

OGC WFS-T

WFS Server Engine Distributed Environment Geographic Object Repository (Postgis, Oracle Spatial, Shapefile, etc.

Methodology Generate the ontology for each integration domain –Terms and Relationship in a formal way The domain ontology is the referential conceptual schema Syntactical and semantic reference for the knowledge area –Uniform Syntax and Semantic for integration Service Oriented Architecture (SOA) Definition Provide Geographic Objects in GML with WFS Knowledge Engineering Process

Methodology Register each domain –Ontologies in OWL Register each GOS in the Integration Server (GeoIS) –Location (URL), Feature Type and Metadata Make the syntactical and semantic correlation among each GOS Schema and the OWL Ontology –WFS DescribeFeatureType OWL Terms Service Oriented Architecture (SOA) Definition Provide Geographic Objects in GML with WFS Knowledge Engineering Process Integration Server Implementation

Methodology Generate and Publish unified Feature Collection with the geographic objects from each data source registered in GeoIS; Preferred formats – GML through WFS Map presentation in WMS. Service Oriented Architecture (SOA) Definition Provide Geographic Objects in GML with WFS Knowledge Engineering Process Integration Server Implementation Integrated Geographic Objects Publication

Methodology Activity Diagram ?

GIS Interoperability New Scenario

Summary Motivation and Goals Conceptualization Methodology Case Study Results Conclusions and Future Works

Case Study Agro-Ecological Palm Oil Zoning in deforested areas in Amazon; Biofuels utilization; Integration of soil geographic data from project data sources; Embrapa; IBGE (web); SIPAM; Others. Domain : Soil attributes to land evaluation.

Study Area IBGE SIPAM

Data Sources Used SIPAM Dual Architecture (Oracle + Shapefile) Scale: 1: All Amazon Region Restrict Information. IBGE Shapefile + dbf Scale: 1: Amazon Boundary region Public Information (

Heterogeneous!!!!

Materials PostGIS SIPAM Geographic Data Source - conversion from dual architecture (Shapefile + Oracle) to spatial database PostGIS; ArcGIS IBGE Geographic Data Source (shapefile) - unification of geometry and necessary attributes; GeoServer Configuration of WFS Services; Protégé OWL Creation of Knowledge Base in OWL Java J2EE Server Integration Application Geotools 2.1 – WFS Functions utilization and result generation Protégé OWL API – Get Ontology terms to correlation

Methodology Application Service Oriented Architecture (SOA) Definition IBGE Data Source (Soils) SIPAM Data Source (Soils) cartas_fronteira.shp

Methodology Application Service Oriented Architecture (SOA) Definition Provide Geographic Objects in GML with WFS

Query Server Capabilities Server Name Feature Type Name

Query Server Schema (XMLSchema) GML MultiPolygon Type All Schema in XMLSchema

Methodology Application The Knowledge Engineering Process Interactive Process - GIS Experts and the researches from Embrapa Soil Research Center Generation of 3 Knowledge Bases (Ontologies): i) soil attributes for land evaluation; ii) land evaluation in general; iii) land evaluation specific for palm oil; Ontology Editor: Protégé OWL Service Oriented Architecture (SOA) Definition Provide Geographic Objects in GML with WFS Knowledge Engineering Process

Methodology Application Knowledge Base

Map Unit is-a FeatureType Ontology and GML Integration Map Unit Properties

Methodology Application Land evaluation soil attributes (AtributosSoloAptidao.owl)

Methodology Application Java Implementation Important Open Source Java Libraries used: Protégé OWL API Geotools Service Oriented Architecture (SOA) Definition Provide Geographic Objects in GML with WFS Knowledge Engineering Process Integration Server Implementation

Domains

Ontology file (OWL) Geographic Data Sources

Domain Relationship Metadata Service Location FeatureType Name Correlation Table

GOS Property Schema Ontology Terms (Reference Schema)

Methodology Application New Map Registration Creation of integrated map All the geographic objects (features) from different data sources with the same schema Output Format: Shapefile (for this case study) Service Oriented Architecture (SOA) Definition Provide Geographic Objects in GML with WFS Knowledge Engineering Process Integration Server Implementation Integrated Geographic Objects Publication

New integration map

Geographic Data Sources that must be integrated

Download integrated map files

Summary Motivation and Goals Conceptualization Methodology Case Study Preliminary Result Conclusions and Future Works

Same Map Two Different Geographic Data Sources Selected map unit data source (IBGE) Reference Schema Ontology

Another Map Unit Selection Selected map unit data source (SIPAM) Same Reference Schema

Summary Motivation and Goals Conceptualization Methodology Case Study Results Conclusions and Future Works

Conclusions Semantic, format and syntax standardization can be a way to interoperability; The proposed methodology showed good results as a solution to the integration of heterogeneous geographical data sources (when applied to Amazon soil data sources); The use of WFS tools presented potential to unify different formats in GML. Protégé OWL framework succeed in representing experts knowledge; Difficult to work with Geotools and Protégé OWL API – sometimes it is necessary to change the source code.

Future Works Include in the methodology Web Register Service and OGC Catalog Service standards to register the Geographic Objects Servers Services (GOS) and the metadata respectively; Ontology-based querying to distributed geographic objects; Provide different output formats: GML and OWL individuals; Apply the work for all Legal Amazon Region; Make inferences about generated OWL file (automated land evaluation generation).

Questions ? Victor H. M. de Azevedo Thanks for the attention!

Query Feature Collection Geodetic Reference System – Use the EPSG ( Geodetic Parameter Dataset. GEOGCS["SAD69", DATUM["South_American_Datum_1969", SPHEROID["GRS 1967", , , AUTHORITY["EPSG","7036"]], AUTHORITY["EPSG","6291"]], PRIMEM["Greenwich", 0.0, AUTHORITY["EPSG","8901"]], UNIT["degree", ], AXIS["Lon", EAST], AXIS["Lat", NORTH], AUTHORITY["EPSG","4291"]] Feature Data