Implementation of a Data Node in China's Spatial Information Grid Based on NWGISS Dengrong Zhang, Le Yu, Liping Di [email protected] Institute of Spatial.

Implementation of a Data Node in China's Spatial Information Grid Based on NWGISS

Dengrong Zhang, Le Yu, Liping Di

[email protected]

Institute of Spatial Information Technology (ISIT)

Department of Earth Science

Zhejing University (ZJU)

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Introduction SIG Resources and Data Nodes A SIG Data Node Based on NWGISS Application and Efficiency Test Conclusion

Outline

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Introduction SIG Resources and Data Node SIG Data Node Based on NWGISS Application and Efficiency Test Conclusion

Outline

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Introduction

Effectively access and share vast isomerous and distributed spatial data is a key technology for extensive GIS applications.

ISO TC211 and OGC provide standards for sharing and interoperating geospatial information.

Spatial information Grid (SIG) is a web-based infrastructure and technology system of spatial information in China

NWGISS is a web-based, multiple OGC standard compliant data distribution system developed by the Laboratory for Advanced Information Technology and Standards (LAITS), George Mason University.

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Open GIS Consortium (OGC)

Specifications for establishing spatial information grid (SIG) data node include:

– Web Coverage Service (WCS)

– Web Feature Service (WFS)

– Web Map Service (WMS)

– Catalog Service/Web (CS/W)

– Geography Markup Language (GML)

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Introduction SIG Resources and Data Node SIG Data Node Based on NWGISS Application and Efficiency Test Conclusion

Outline

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SIG Application Layer

SIG Assembly Layer

SIG Share Layer

SIG Resource Layer

SIG Connect Layer

SIG Pre-Process Layer

SIG Analyze Layer

Share Spatial Information

Manage Spatial Information

Transfer Spatial Information

Acquire Spatial Information

Geospatial Information Application

(Tang Yu et al, 2004)

SIG Open Architecture

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Spati al Data Fi l es

Spati al Database

Servi ce I nteroperati on

Servi ce

Data Descri pti on & Archi tecture

Protocol

Data Access Servi ce Protocol

Data Access

Data El ement W

Data El ement D

Protocol El ement S

I mage Servi ce

Map Servi ce

Spati al FeatureServi ce

SIG Resource Layer

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SIG Data Node

Function of SIG data node is processing spatial data in distributed spatial data file server, spatial database server, remotely sensed imagery server normatively, organizing data to specific structure for easier managing, accessing and using.

There are two requirements for these node:

– 1) providing coverage services, map services, feature services and catalog services;

– 2） complying with OGC specifications.

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Introduction SIG Resources and Data Node SIG Data Node Based on NWGISS Application and Efficiency Test Conclusion

Outline

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NWGISS Interoperation Data Server Layer

Architecture

Regi ster

Feature I mage Map Metadata Catal og/ Regi ster

OGC Protocol

Web CoverageServer

Web Regi stryServer

Web FeatureServer

FeatureData

HDF-EOS Data Fi l es

Web MapServer

XMLMetadata

Maki ng Capabi l i t i es

Catal og Access

Data/ Servi ce Catal og

I ntegrated NWGI SS OGC Servi ce I nterface

(NWGISS, http://nwgiss.laits.gmu.edu/introduction.htm)

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Structure of SIG Data Node

GeoTi ff数据文件

Formattrasfer

HDF-EOS数据文件

HDF-EOSData Fi l es

WMSMetadata

GeoTi ffData Fi l es

Web CoverageServer

Web Catal ogServer

Web MapServer

SI G NodePortal

Web Servi cePackage

Web Servi cePackage

Web Servi cePackage

SOAP, OGC

HTTP, OGC

SOAP, OGCSOAP, OGC

WCSMetadata

Extracti ngMetadata

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Implementation of SIG Data Node Based on NWGISS

Providing MODIS data to SIG Taking GMU LAITS’s NWGISS as core software WCS 1.0 standard compliant Three formats: HDF-EOS4, GeoTiff, NITFF ISO19115 international standard was employed to describe th

e dataset ISO19119 was employed to register the data access service

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Introduction SIG Resources and Data Node SIG Data Node Based on NWGISS Application and Efficiency Test Conclusion

Outline

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Application

To validate the SIG data node, a SIG validating platform is established. Environment of OGC web service, the function of SIG service registration center, spatial information retrieval engine, engine for assignments management and services coroutine and resource management are validated by this platform.

All interface in SIG data node comply with OGC specifications. Three access modes will be adopted for different application intention, there are:

– Web Service mode

– Web application mode

– Desktop application mode

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Efficiency evaluation

Responding to standard OGC requests and return specific spatial data under different network environment

Any OGC WCS1.0-compliant geospatial information analysis system client can access the data nodes distributed at different location and get back geospatial data and completes comprehensive analysis locally

Interoperable accesses between windows data node and Linux data node also shows a good capability of data sharing under isomerous operation environment

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Introduction SIG Resources and Data Node SIG Data Node Based on NWGISS Application and Efficiency Test Conclusion

Outline

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Thank you for your attention!Thank you for your attention!