I N D I A N I N S T I T U T E O F R E M O T E S E N S I N G , D E H R A D U N

Geo-Web services based framework for

development of Mashup applications in GIS

Dr. Harish KarnatakHead

Geoweb Services, IT & Distance Learning DepartmentIndian Institute of Remote Sensing (IIRS), ISRO Dehradun

harish@iirs.gov.in

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Geo-Information Services Technological Overview

…how it works?

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Knowledge Base for GISApplication Area:public admin.planninggeologymineral explorationforestrysite selectionmarketingcivil engineeringcriminal justicesurveying

ComputerScience/MISgraphicsvisualization databasesystem administrationsecurity

Geographyand related:cartographygeodesyphotogrammetrylandformsspatial statistics.

The convergence of technological fields and traditional disciplines.

GIS

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GIS System Architecture and Components

Information system

External and Internal data

Decision maker

• Database Server-DatabaseManagement

• Application server-Applicationsoftware

• Hardware

Major ComponentsData Management; Spatial & Non-

spatial data

Model Management; Spatial model & Non-

spatial model

Knowledge Management

Dialog Management; Attribute base query and report; Spatial

query and spatial output

Attribute data

Spatial data

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Network Based Geo-Information Services

Web clientsGatewayData

GIS Server

Web/application server Web users

User 1

User 2

User 3

User 4

User n

Request

Response

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Client end

Web browser

Thick client

Other web client

WEB

SERVEr

Application Server

GIS/M

ap ServerRequest

Response

Data Server

Fig.-11.4. Typical architecture for Internet base geo-spatial data access

Network Based Geo-Information Services

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Network Based GIS- Example

Web/Internet GIS; Enterprise GIS; Distributed GIS; Mobile GIS; … etc many more examples.

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What is Web GIS ?The integration of GIS and Internet technologies is allowingGIS professionals to solve one of the most importantproblems inhibiting information utility: How to provideaccess to information and data without burdening endusers with complicated and expensive software. Internet isa perfect means of GIS data accessing, analyzing andtransmission.

The World Wide Web, FTP (file transfer protocol) and HTTPprograms make it convenient to access and transfer datafiles across the Internet. The Internet provides GIS userseasy access to acquire GIS data from diverse data source indistributed environment. GIS users can use and downloadthe data by sending the request through web browserapplication.

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Web GIS- Basic Properties Web GIS technology is dynamic, for example, once any client (s)

or database administrator updates the data or information atserver end, it will available for all the clients on web at the sametime.

The Internet GIS can also link with real time information, such assatellite images, traffic movements and accident information byreal time connection with the relevant information sources.

The applications developed are cross-platform and accessiblethrough any web browser.

The Internet GIS applications can categorize into two majorcategories i.e. server-side applications and client-side applications.Server-side applications rely on GIS server (usually reside on aremote server) to perform all GIS analysis, while client-sideapplications perform GIS analysis and processing in the Webbrowser on the user’s local machine.

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A Typical Web Client/Server Model

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• Standards-Based• Cross-Platform• IT Focused

OpenPlatform

GIS Server

Mapping -Visualization

DataServices Editing Geoprocessing

ServicesCatalogServices

Geo-RDBMS

Providing Centralized GIS Services

Centralized & Distributed GIS Development and Processing

Standard Web Services

Full GIS Servers are Emerging

XML StandardsDistributed Computing

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Web GIS Server ComponentsDatabase Server:

The database server may have a file based system or RelationalDatabase Management System (RDBMS) based or a combinationof files and RDBMS

GIS or Map Server:Map server or GIS server is a software package or program, whichis responsible for rendering the GIS data into web browser

Application Server:An application server is a software which provides customizedsoftware applications.

Web Server:A web server is a computer program which uses the client/servermodel and the World Wide Web's Hypertext Transfer Protocol(HTTP), serves the files that form web pages to web users

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Web 2.0 and GIS

Web 2.0 is referred as an interactive webapplication with public participation which allowsparticipatory information sharing,interoperability, user-centered design, andcollaboration on the World Wide Web.

The integration of web 2.0 with GIS dataapplication is known as GeoWeb 2.0.

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Web as platform

Participation

Content syndication

Web services Conceptual &

social

TechnicalXML RSS JavaScript AJAX …

Web 2.0

…..………

Web 2.0 and GIS

Web 2.0 can be realized by combining several webcomputing technologies such as AJAX, Open API, REST,XML, XHTML/CSS, RSS/GeoRSS and other relatedtechnologies.

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Service Oriented Architecture (SOA)

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Service Oriented Architecture (SOA) for GIS

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Differences between a Website & Web Services

WebsitesProvide HTML pages andforms for human users tonavigate and performfunctions Searching, Shopping,

Interaction

Front end user interfacesthrough the browser

Example: www.google.com

Web ServicesNOT websitesOperations that can becalled to returninformationInvoked automaticallythrough a programPublicly available andstandardized for use byall programmers

Example: ?

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The Open Geospatial Consortium

Vision:Develops standards for geospatial web services

Mission: A world in which everyone benefits from geographic information and services made available across any network, application, or platform

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OGC Provides Interoperability

OGC Specifications are agreed upon by a broadconstituency of the geospatial community andare supported by many software vendors

OGC links geographic data with mainstreamInformation Technology (IT)

Vendor implementation in products enables thedirect access and use of data produced byprograms from many vendors

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OGC and Standards Organizations

OGC collaborates and work closely with: International Organization for Standardization

(ISO) TC 211 and 204World Wide Web Consortium (W3C) Internet Engineering Task Force (IETF) OASIS Automotive Mobile Information Consortium Open Mobile Alliance And others…

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Types of Web Service Specifications for GIS

Catalogue Services (Examples- CS Core,CS-W ebRIM, CS-W19115/19119 and CS-W ebRIM for EO)

Processing Services (Examples- Sensor Planning Service(SPS), and Web Processing Service (WPS), CoordinateTransformation Service (CTS and Web Coverage Processing Service(WCPS)).

Encoding ( Examples- Geography Markup Language (GML),CityGML, GML Simple Features, Filter Encoding (FE), GML in JPEG2000, KML, Observations & Measurements (O&M), Sensor ModelLanguage (SensorML), Symbology Encoding (SE), Styled LayerDescriptor (SLD), SWE Common, Transducer Markup Language(TML).

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Data Services (Examples- Simple Features Specification (SFS),Web Coverage Service (WCS), WCS Transactional, SensorObservation Service (SOS), Table Join Service (TJS) and WebFeature Service (WFS).

Portrayal Service (Examples-Web Map Service (WMS) andWeb Map Tiling Service)

Other Services (Examples- GeoXACML, GeoRSS, Geospatial Objects, OWS Common)

Types of Web Service Specifications for GIS

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Geospatial Web Service Flow- Example

User Applications

Data Discovery

CatalogCatalogCatalogs

Geospatial Web Services

Features

ContentRepositories

Coverages

Data Visualization

Data Access

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Approved Specifications of OGC

Simple Feature Access – OLE, SQL, CORBA Catalog 1.1.1 Coordinate Transformation 1.1 Grid Coverages 1.0 Web Map Service 1.1.1 (2.0 in final edit) (WMS) Geography Markup Language 3.0 (GML) Web Feature Service 1.0 Filter 1.0 Style Layer Descriptor 1.0 (SLD) Web Coverage Service 0.0 (WCS) OpenLS OGC Web Services (Ongoing) Web Map Client Configuration

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What Does All This Do for You?

‘Near instant’ data interoperability Access and exploit a wide variety of spatial data on-demand No more time spent translating files to your format or projection

Supports web based services architecture Get your GIS over the web. Choice of web-based tools Locate information across a distributed environment using different

vendor applications, different projections

No more data configuration management Get your answer from the latest data when you need it Reduce data maintenance costs. Access and maintain only the data you

care about

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Mapping on the Web Today

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Mapping on the Web Today

How can I combinedata from each ofthese sources toanswer myquestion?

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OGC Specifications CSW - Catalog Service for the Web: access to catalog information.

This standard is very important to create a spatial datainfrastructure through which the discovery of geospatial data fromdifferent data sources are possible. It can work as a clearing housefor geospatial data in SDI.

GML - Geography Markup Language: XML-format for geographicalinformation used for exchange geospatial data. The GML can handleboth the vector and raster data in 2D and 3D domain.

KML - Keyhole Markup Language: XML-based language schema forexpressing geographic annotation and visualization on existing (orfuture) Web-based, two-dimensional maps and three-dimensionalEarth browsers. Initially KML was a proprietary data standard ofGoogle but now it is accepted by OGC as one its standard for 2Dand 3D geo-visualization.

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OGC Reference Model - a complete set of referencemodels

OWS - OGC Web Service Common SOS - Sensor Observation Service SPS - Sensor Planning Service SensorML - Sensor Model Language SFS - Simple Features - SQL Styled Layer Descriptor (SLD): This specification is

used to define colors (legend) for thematic data. It is aXML based standard which allows to represent variouscartography contents for map including specialcharacters and symbols.

OGC Specifications

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WCS - Web Coverage Service: provides access,subsetting, and processing on coverage objects. Thisservice specification is used for raster or gridded data. Ifdata is served as WCS then a simple URL will act as aImage data and all the Image processing relatedactivities can performed with this URL. This is a dataservice specifications for raster data.

WCPS - Web Coverage Processing Service: provides araster query language for ad-hoc processing and filteringon raster coverages.

OGC Specifications

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WFS - Web Feature Service: for retrieving or alteringfeature descriptions. This is a specification for vectordata sets. Once the vector data is served as WFS then allthe vector operation including overlay analysis can beperformed with simple URL. This is a data servicespecification for vector data.

WMS - Web Map Service: provides map images forraster as well as vector data. This service specification isused for geo-visualization purpose.

WMTS - Web Map Tile Service: provides map imagetiles for map caching at client end. Used to enhance theperformance of Web GIS applications.

OGC Specifications

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WPS - Web Processing Service: remote processing service

GeoSPARQL - Geographic SPARQL Protocol and RDF Query Language: representation and querying of geospatial data for the Semantic Web

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Mashup Applications in GIS

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Mashup GIS Applications

Mashups, composed of mixing different types ofsoftware and data from variety of sources todevelop a user defined GIS applications in theform of software blending applications.

Also known as ‘Neogeography’ in which non-expert users are able to exploit the power ofmaps (Michael Batty, 2010).

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Typical Mashup Architecture- Case

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Practical Exercise1. Access Bhuvan Geoportal and browse 2D viewer2. Identify Area of Interest and Draw AOI3. Download AOI as Shape file4. Open project in QGIS and set SRS as 43265. Open AOI and set symbology6. Call WMS of Satellite Image and Thematic data7. Call WFS of Vector data8. Install OpenLayer Plugin in QGIS9. Call Google Maps (Satellite and Physical) and Ovelay10. Call other map services like Yahoo, Bing etc11. Access OSM website and download the data12. Access Geofabric website and download shape file of vector layers13. Overlay OSM data in QGIS project14. Understand OSM data structure15. Extract attributes and feature from OSM data16. Download satellite data and stack it as FCC and overlay in QGIS project17. Connect remote server for ground truth data (like ODK)18. Demonstrate field data collection using mobile app19. Integrate field data into QGIS project

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