m tech project presentation

Integrating Heterogeneous Geospatial DataRepositories Using Geospatial Modeling and

Geospatial Web Services.

Vivek Chaure [07CS6006]

Under the guidance of

Prof. S. K. Ghosh (School of I.T.) andProf. J. Mukhopadhyay(Dept. of C.S.E.)

Indian Institute of Technology, KharagpurMay 6,2009

Outline

Introduction

Problem Statement

Related Work

Architecture of the framework

Geospatial Data Modeling

Modeling Temporal Dimension

Model Checker

Service Based Interoperable Framework

Conclusion and Future Work

Introduction

GIS : An Information System which captures, stores, and analyzes data that refers to geographic location.

GIS applications : A collection of tools that allow users to create

interactive queries, analyze spatial information, edit data, maps,

and present the results of all these operations.

EGIS : A geographic information system that is integrated

through an entire organization so that a large number of users

can manage, share, and use spatial data and related information

EGIS Scenario

Figure: An EGIS scenario (Spatial Data Provider’s Repositories: R1, R2,R3. All data models should confirm to the Global Data model specified bythe EGIS.)

Heterogeneity

Characteristics of Geospatial data:

Represent geographic locations with coordinates.

Has spatial and non-spatial attributes

Spatial relationship with other entities in a data set.

Temporal property - evolution over time.

Figure: Land Suitable for farmingGeodetic Framework

Land Use

Infrastructure

Soil

Hydrology

Interoperability The ability of two or more systems or components to exchange

and share information.

Problems in sharing Geospatial information:

Political, Institutional and Economic Problems: Copyright , Sensitive data etc.

Technical Problems: Heterogeneity

Reasons for heterogeneity:

Layers created under different contexts.

Different access mechanism [flat file/database]

Diverse Data Formats

Storage mechanisms [disk / tapes]

Interoperability

Types of Heterogeneity

Syntactic Heterogeneity - Proprietary Packages use proprietary internal representation which is sharable among proprietary organizations.

Structural Heterogeneity - “Water bodies overlapping a city” or “water bodies within a city”

Semantic Heterogeneity - “Mauza” or “Village”

A model driven framework can overcome the technical problems of Syntactic and Structural Heterogeneity involved in achieving interoperability.

A model driven framework guarantees security of underlying geospatial data.

Problem Statement

A geospatial interoperable framework has to be implemented using a relational database with spatial capabilities.

The framework shall support spatial and spatio-temporal data.

In order to achieve interoperability, the framework uses data exchange standards such as Geography Markup Language(GML), and web service specifications such as Web Map Service (WMS) and Web Feature Service (WFS) as specified by the Open Geospatial Consortium (OGC).

Problem Statement

Objectives :

Design of Geospatial Data Model using UML based on the spatial features.

Generation of GML Application schema from the UML data model and populating the database with data provided in GML form conforming to the Application Schema. – A standard encoding scheme.

Extension of Geospatial model to support spatiotemporal properties. Design the geospatial model to represent spatiotemporal features, by extending UML.

Integration of heterogeneous geospatial repositories in a geospatial services based interoperable framework.

Approach Geospatial Data Modeling for Village connectivity is designed. And the

standard encoding scheme is used to populate data sources.

Extended UML notations are used to design a model for the domain of Education.

The service based interoperable framework is designed based on the models for village connectivity and settlements.

Tools and Standards:

IBM Rational Rose – For modeling spatial / spatiotemporal models.

Shapechange – For generation of application schema.

Oracle 10g Spatial Database

OGC Standards for Geospatial web Services.

Related Work Geospatial Data Modeling :

Climate Science Modeling Language [Woolf , 2006]

Dept. of Homeland Security Geospatial Data Model(DHS-GDM) [2]

Modeling Temporal Dimension TimeDB [Carvalho, 2006]

Spatio-temporal E-R diagrams (STER) or Spatio-temporal UML diagrams (STUML) [Wang,2000]

Aeronautical Information Exchange Model (AIXM) -2007 [5]

Online and offline UML Model Comparison [Girschick ,2006],[Xing,2005]

Related Work

Geospatial Standards A modeling approach based ISO rules of application schema

[ISO,2001] has been specified in [Jang,2006] .

Geography Markup Language (GML) as a standard means for encoding[GML,1980]

The OGC has developed a specification for a software framework which involves Web Map Service, Web Feature Service and Web Coverage Service are classified as transmitted data style.[Hyun2000]

Architecture

Oracle Database

Match?

yesyes

MM = Model MatcherQM = Query Model

Geospatial Data Modeling

Achieves Syntactic and Structural interoperability in geospatial data sources.

RoadCategory

Metalled : <undefined>Unmetalled : <undefined>

(from BlockRoad)

<<enumeration>>

AdministrativeBoundary(from BlockRoad)

NSDIThemes(from BlockRoad)

<<FeatureCollection>>+NSDIThemes

Block

Block_id : stringBlock_name : string

(from BlockRoad)

School

School_name : string

(from BlockRoad)

Communication(from BlockRoad)

+NSDIThemesMember

+NSDIThemesMemberVillage

Village_name : string

(from BlockRoad)+BlockMember

Settelement

Village_id : string

(from BlockRoad)

+in

+contain

Road

raip_roads : stringroads_type : RoadCategorylinearGeometry : GM_Curve

(from BlockRoad)

*

1

+CommunicationMember

*

+CommunicationMember

1

+connect

Realization

Aggregation

Unidirectional Association

Bidirectional Association

Standard Encoding Scheme

Road

Road_id : numberRoad_type : RoadTypelinearGeometry

Conversion Rules

<complexType name= “RoadType”><complexContent><extension base= “gml:AbstractFeatureType”><sequence><element name=“Road_id” type= “string”/><element name=“Road_type” type= “string”/><element name=“linearGeometry”type= “gml:LineStringPropertyType”/></sequence></extension></complexContent></complexType>

Village Connectivity<<ApplicationSchema>>

<schema xmlns="http://www.w3.org/2001/XMLSchema" xmlns:SoI="http://www.nrdms.gov.in" xmlns:gml="http://www.opengis.net/gml" elementFormDefault="qualified" targetNamespace="http://www.nrdms.gov.in" version="1.0">

<import namespace="http://www.opengis.net/gml" schemaLocation="feature.xsd"/>

Fig: Creating UML Schema using IBM Rational Rose.

Fig: Creating GML Application SchemaUsing rules of conversion

Export

XMI

XMI

GML

The GML schema generated from UML Class diagram is further mapped into object oriented database along with GML data by using a GMLtoOracle parser.

Standard Encoding Scheme

Fig. Standard Encoding SchemeFig. Tables created using Standard

Encoding Scheme.


Spatiotemporal features : Objects with continuous motion:

moving objects like sea creatures being tracked by GPS.

Discrete changes of and among objects;

landparcels, rivers change their position discretely.

Motion as well as changes of shape.

storms.

Benefits : Improved support for Time variant geo-referenced information.

Can provide snapshot view or history of evolution of a spatial feature.

Event based or State based temporal analysis can help in decision making.


Limitation of UML Notations:

It is possible to enter each temporal attribute of a class into a separate associated class with the timestamps and spatial extents as attributes.

creation of artificial constructs to convey temporal semantics which would significantly complicate the schema diagram.

School

Schoolid : IntegerName : String

SchoolType

Purpose : String

Purpose

SchoolId : IntegerTypeId : IntegerPurpose : StringFrom : DateTo : Date


Remedy - Create symbols which adds spatio-temporal semantics to traditional UML notations.

Temporal database concepts of Valid time and transaction time are required to be implemented.

We use the semantic notations from Spatio Temporal UML (STUML) to represent the spatio-temporal characteristics of attributes.

A specification Box – describes nature of time interval.

Fig: Basic Constructs


Fig: Primitives Used in Modeling Spatiotemporal Data

Grading is done depending on the number of students passed in each year

District

DistrictName : string

Block

BlockName : string

*

1

*

+contain1

Grading

TotalStudent : numberStudentPassed : numberYear : stringGrade : string

Village

VillageName : stringPopulation : <d:int<s<t>>>

*

1

*

+contain 1

Road

RoadType : stringRoadName : stringFNode : intTNode : intRoadLink : string

Teacher

TeacherID : numberTeacherName : stringDOB : datejoinedOn : dateRetirementOn : dateAddress : string

Purpose

FromDate : dateToDate : datePurposeType : purposetypedetails : string

Specification Box for population:Time Dimen:validTime Model:regular(Yearly)

SpecificationBox Grading:TimeDimen:transactionTime Model: regular (yearly)

School

SchoolId : numberSchoolName : stringShape : pointestablished : dateSchoolType : <d:string<t>>

+has <d:int<t>>

1

*

1

+inside <s>*

+near <t>

+has<t>+to state2

+from state1

+used as <t>

Students

StudentRollNo : numberStudentName : stringDOB : dateAddress : string

+has<t>

SpecificationBox PurposeTimeDimen:transactionTime Model:irregular

SpecificationBox StudentsTime Model:irregular

SpecificationBox TeacherTime Model:irregular

Modeling Temporal Dimension• Spatiotemporal Model of Education domain:

• Yearly school grading based on number students passed in each year.

• The schools are used for other purposes such as election booths, relief camps during flood drought etc.

Representing Spatio-temporal Features in Database:

History Table for each temporal feature.

History of association named “near” between School and Road features.


SID

S1

S2

:

Sn

Sname

SBC

AGT

:

..

Shp

1,1

4,6

:

..

School Table

est

12/06/06

23/01/07

:

..

TKey

T1

T2

:

Tn

RdNear

R2

R2

:

..

Stype

H

H

:

..

Tkey

T1

T1

T2

Stype

P

RdNear

R1

R2

TI

t1-t2

t1-t4

t1-t3

School History Table

SchoolID: integerSchoolName: string

School

Established :DateSchoolType : <d:string<t>>

Operation

Road

Operation

RoadName: stringRoadType: string

Near<t>

RdName

R1

R2

R3

Rtype

Type1

Type2

Type1

Road Table

Sample Queries

Query 1 : Count of schools in “village 1” and “village 2” between years 2000 to 2005.

Query 2 : Grades of school 1 between years 2001 to 2004.


Fig: Results of Query 1

School Name Grade Year

School1 A 2001

School1 B 2002

School1 A 2003

School1 A 2004

Fig: Results of Query 2

Model Checker

Need:

The service provider’s models are to be harmonized with the global data model.

Equivalence check

M2 is said to be equivalent to M1 if M2 M1.⊆

Automata design tools can be used for checking properties of models.

Model Checker

Simple PROMELA Interpreter (SPIN) has been used for checking properties of models.

A model is simulated as a procedure say Global() and Submodel()

proctype Global(){atomic {

run School(0,1,1); //featureinside[1]=true; // associationrun Village(1); //feature

}}

proctype Submodel(){atomic {

run School(1,0,1); //featureinside[1]=true; // associationrun Village(1); //feature

}}

School

SchoolId : IntegerSchoolName : String

Village

VillageName : String+inside

School

SchoolName : StringVillage+inside

Model Checker

Classes , Attributes and associations are also modeled as procedures.

Sc[0] and v[0] are Boolean variables indicating presence of a class in model 0 i.e. Global model.

a LTL formula Fɸ or symbolically, <> ɸ meaning that Property ɸ eventually holds somewhere in subsequent path in automata.

Properties to verify:

#define match ((sc[0] | sc[1])==true && (v[0] & v[1]) == true) ..[1]

#define unmatch ((!sc[0] & sc[1])==true || (!v[0] & v[1])== true) ..[2]

To verify the match with respect to associations the following property is defined:

#define asso (inside[0] & inside[1]==true) ..[3]

Model Checker

Results of model comparison:

If a UML model could be represented as an automata, such a Model checking tool can be integrated into the proposed framework.

Service Oriented Architecture

Web Service - a software interface that describes a collection of operations that can be accessed over the network through standardized XML messaging.

Allows applications to communicate with each others in a platform independent manner.

Figure: Web Service Model

Geospatial Web Services

Figure: Geospatial Web Services


The aim of this design is to be able to be able to integrate services representing isolated data repositories at a central location called a Registry Service.

Figure: Design Aim of framework

Registry Service

OGC Client

Geospatial Repository1

Geospatial Repository2


The IITKGP Geoservice is an implementation of basic services WMS and WFS. Apart from these basic services a Registry service is to be introduced in order to implement the central location.


Web Registry Service (WRS)

- run-time discovery and evaluation of resources

- maintains a directory or metadata information about each Data provider.

Service metadata includes location, point of contact information and other keyword information that uniquely identify the service.

Operation metadata specifies the operations which are offered by a service.

WRS requests : GetCapabilities :

RegisterService - for registration of a service and

GetDescriptor - for handling client queries this request harvests metadata from other services.


Figure: Interface Diagram for proposed framework

Integrated Client WRS W*S

getCapabilities()

return XML

getRecordRequest()

return XML

getCapabilities()

return XML

Application Scenario

• All the Web feature and Web map services advertise their metadata to the Web Registry Service through a interface for catalog service.

• An assumption is made that other data providers follow the global schema.

•Catalog Service (CSW) Requests:• GetRecordById()• GetRecords() - GetDescriptor() of

WRS• Transaction() - RegisterService() of

WRS


WFS_SettlementsWFS_transport

Fig: WFS_Base Data Model

Application ScenarioStandard encoding scheme is used to populate transport and settlement data at respectiveData Sources.

Fig: GML Application Schema Fig: GML Data

Service Based Interoperable FrameworkWe use the metadata in catalog service to implement functionality of a registry service.

Service Metadata

Operation Metadata


1. Data Providers Advertise Service Metadata

2. Client determines service to be contacted using metadata and redirects query

3. Query Results


Query Model1: “Which schools are inside Block1”

Queries

Query Model2 : “Which railway line is crossed by NH1”


Query Model3: “Which are the resorts in Block1”

Queries

Query Model4: “Which bridge canBe taken to cross railway line code 1034”


Figure: Results for Query 1


Figure: Results for Query 2


Figure: Results for Queries 3 and 4


Sharing geospatial information has become an issue to be addressed because of its heterogeneity.

A standard data model is essential for data sharing to be effective. We have addressed the problem of syntactic heterogeneity.

An Object oriented modeling approach for geospatial data and demonstrates a standard encoding scheme takes the structured geospatial data (GML) into an object relational database (Oracle 10g Spatial).


we used additional constructs to UML model that represent the semantics of spatio-temporal data. These features were also represented in the database using additional tables to maintain feature history.

The proposed framework is based on the service-based computing paradigm and adheres to the OGC specified interface standards.

Future Work:

Loosely Coupled Web Services

Model Checking

References[Hyun,2002] Do-Hyun ,Kim M. K., “Web GIS Service Component

Based On Open Environment” ,IEEE ,2002.

[Woolf , 2006] A. Woolf, B. Lawrence, R. Lowry, K. Kleese van Dam, R. Cramer, M. Gutierrez, S. Kondapalli, S. Latham, D. Lowe, K. O’Neill, and A. Stephens, “Data integration with the climate science modelling language,” Advances in Geosciences, vol. 8, pp. 83–90, 2006. [Online]. Available: http://www.adv-geosci.net/8/83/2006

[Carvalho, 2006] A. S. A. Carvalho, C. Ribeiro, “A spatio-temporal database system based on timedb and oracle spatial,” in Proceedings of the IFIP International Federation for Information Processing, 2006, pp. 11–20.

References[Wang,2000] X. Wang, X. Zhou, and S. Lu, “Spatiotemporal data

modeling and management: A survey,” in TOOLS ’00: Proceedings of the 36th International Conference on Technology of Object-Oriented Languages and Systems (TOOLS-Asia’00). Washington, DC, USA: IEEE Computer Society, 2000, p. 202.

[Girschick ,2006]T. D. Martin Girschick, “Di erence detection and ffvisualization in uml class diagrams,” TUD-CS-2006-5, 2006. [Online]. Available: http://www.mm.informatik.tu-darmstadt.de/sta /girschick/publicffations/2006 umldi cld.pdfff

[Xing,2005] Z. Xing and E. Stroulia, “Umldi : an algorithm for ffobject-oriented design di erencing,” in ASE ’05: Proceedings of ffthe 20th IEEE/ACM international Conference on Automated software engineering. New York, NY, USA: ACM, 2005, pp. 54–65.

References[ISO,2001] Rules for application schema, ISO (2001b),Final text of

CD 19109,Geographic information ISO/TC 211 N 1127, 2001.

[Jang,2006] S.-G. Jang and T. J. Kim, “Modeling an interoperable multimodal travel guide system using the iso 19100 series of international standards,” in GIS ’06: Proceedings of the 14th annual ACM international symposium on Advances in geographic information systems. New York, NY, USA: ACM, 2006, pp. 115–122.

[GML,1980] OpenGIS Geography Markup Language (GML) Implementation Specification. New York, NY, USA: ACM, 1980.

Thank You.

m tech project presentation

Documents