ISPRS WG II/3 Chongjun YANG [email protected] Sept. 15-19th 2003, Thailand Co-Chair of ISPRS WG...
-
Upload
alexander-parker -
Category
Documents
-
view
212 -
download
0
Transcript of ISPRS WG II/3 Chongjun YANG [email protected] Sept. 15-19th 2003, Thailand Co-Chair of ISPRS WG...
ISPRS WG II/3
Chongjun [email protected]
Sept. 15-19th 2003, ThailandCo-Chair of ISPRS WG II/3
IRSA/Chinese Academy of Sciences
WG II/3 Terms of References and Activities •Systems for integrating geo-spatial data •Integrated services involving economic, technical and political aspects •Geo-spatial information distribution and accessibility systems using internet •Development and validation of end-to end spatial data access systems• Liaison with CEOS WGISS and other relevant organizations
ISPRS Working Group II/3
Integrated Systems for Spatial Data Management
http://www.digitalearth.cn/wgII-3
Interoperability of Spatial Data Service
Chongjun [email protected]
Sept. 15-19th 2003, Thailand
Co-Chair of ISPRS WG II/3
IRSA/Chinese Academy of Sciences
Interoperability of Spatial Data Service
For Open System
1. Context 2. Components of Interoperability3. Levels of Interoperability4. Criteria for Interoperable System 5. XML,GML,WMT,C#, .NET6. Example7. Discussion & Cooperation
Interoperability of Spatial Data Service
1. Context : GIS Computing
Computing-Structured(Standlone System)
Computing-Centred(Centre- System)
Client-Server System(Local Network)
Computing-Distributed
System(Intranet/Internet)
Data
Decision
Knowledge
Information
Service
1. Context
Data
1. Context : Trends
Service
GI IT mainstream
1. Context : Interoperable Mechanism of Internet
Internet : TCP/IP
Web: HTML(XML)
HTTP
API
URI
Little interoperability for spatial data
1.Context : Benefits of interoperable spatial data service
(1) eliminating spatial data duplication.
(2) reducing the effort required to manage and maintain spatial data.
(3) facilitating application development activities.
(4) providing a flexible computing environment with access to computing resources ranging from desktop machines to high-performance computers (supercomputers); and
(5) reducing costs associated with data acquisition, management, maintenance, and conversion, model development, and overall operations.
- How should the exchanged data be represented? (data representation)
- How should two systems communicate? (application communication protocol)
- How should data be addressed across systems? (naming mechanism)
- Which functionality should be available between systems? (application programming interface).
2. Components of Interoperability
3. Levels of Spatial Data Service Interoperability
The more the interoperability
mechanism “knows” about the spatial
data, the advanced the degree of
interoperability is.
No knowledge about spatial data
knowledge of the structural (syntactic) aspects of the data
knowledge of the schematic aspect of the data
knowledge of the semantic data aspect
1) DATA KNOWLEDGE
From simple to advanced interoperability:
3. Levels of Spatial Data Service Interoperability
2) scope of the data model
3) Name Space Management
4) Capabilities of Server API
3. Levels of Spatial Data Service Interoperability
(1) Decisive interoperability criteria,
(2) Technology criteria, and
(3) Implementation and software criteria.
4. Criteria for Interoperable System
Common data representation: Which data types are supported? level of data representation? is it public? is it a standard?
(1) Decisive Interoperability Criteria
Server interface: which functionality is supported? is it extensible? Is it flexible? is it public? is it a standard?
(1) Decisive Interoperability Criteria
Java
COM/OLE
CORBA/J2EE
GRID
…
(2) Relevant Technology Criteria
Format-to-common format conversion via the data server:
- Availability of software products (is a complete, stable system available?)
- Diverse platform support (is the product available for most platforms?)
- Software maturity
- Support and Maintenance
- Cost of software
- Ease of hosting data via the system
(3) Relevant Implementation and Software Product Criteria
• Recommended by W3C in 1998, XML (eXtensible Markup Language) emerges as the second generation Web language for data interchange on the Web.
• Provides text encoding of all data.• Uses a Document Type Definition or Schema
to ensure document/data consistency.• Over 200 XML derived languages.• Offer real potential to significantly impact
geo-spatial data and systems interoperability on the Web.
5. XML,GML,WMT,C#, .NET: XML
• GML Project launched at OGC meeting, April 1999
• GML provides a standard means to encode Geographic Info in XML.
• GML separates content from presentation. GML is focused on capturing geographic content.
• GML is “styled” into a presentation format such as SVG(Scalable Vector Graphics) for map drawing or other visualizations.
• GML is consistent with existing OGC standards for expressing geographic features.
5. XML,GML,WMT,C#, .NET: GML
GML DataServer
Styling EngineMap Style
Library
HTTP TCP/IP
Stylesheet
Map Viewed inWeb Browser
Graphical rendering
Figure. Process of GML Web Mapping
The Web Mapping Testbed, Phase I, is the first of OGC's
planned Interoperability Initiatives, which involve
sponsors and participants. Federal agency and corporate
sponsors provide funding and a set of objectives related
to geoprocessing interoperability. WMT has so far
demonstrated two types of applications: Web Mapping
Clients, and Web Mapping Servers. The Clients create
requests that satisfy the Web Mapping Protocols.
5. XML,GML,WMT,C#, .NET: WMT
The main interfaces are the GetMap protocol (which
identifies one or more layers to be displayed), the
GetCapability Protocol (which allows the client the
ability to discover the abilities of a server), and finally the
GetFeatureInfo protocol (which allows the client to
uncover the attributes of a displayed feature). Web
Mapping Servers interpret requests that conform to the
WMT protocols and generate appropriate objects that are
returned to the querying clients.
5. XML,GML,WMT,C#, .NET: WMT
C and C++: powerful and flexible, but unproductive
C# — Microsoft solution, a modern, object-oriented
building applications for the new Microsoft .NET
serving both computing and communications
.NET — Internet-based integrated solution
5. XML,GML,WMT,C#, .NET: C#, .NET
6. Example6. ExampleA New Spatial Search Engine
– Enabling the Intelligent Geographic Information Retrieval in Internet
Yuqi,BAI Chongjun YANG Yuqi,BAI Chongjun YANG
Institute of Remote Sensing ApplicationsInstitute of Remote Sensing Applications
Chinese Academy of SciencesChinese Academy of Sciences
http://www.digitalearth.cn
Context:
Using “www.yahoo.com” to search a text
Using “www.mapquest.com” to search a
map
Question:
May we search a map
without using “traditional search engine?
6. Example6. Example
Scenario:
When you are reading news on the web, you maybe meet a place name, for example ‘Afghanistan’, and want to know where it is. Can you just simply select this place name and get the corresponding map?
6. Example6. Example
a.Design of a ‘New Spatial Search Engine’-1
Compatibility
Data Sharing
Modularity
Component Sharing
Interoperability
Service SharingThree Stages:
<-
6. Example6. Example
a.Design of a ‘New Spatial Search Engine’-2
Design goals Automation:
get command -> query -> render the result Interoperability:
with any web mapping systems Integration:
can be integrated with other existing applications seamlessly and easily.
6. Example6. Example
a.Design of a ‘New Spatial Search Engine’-3
Conceptual Design Modularization:
For the Web Mapping Systems(WMS) Description:
For the service interfaces of WMS Registration:
a logically centralized, physically distributed registry centre
6. Example6. Example
a.Design of a ‘New Spatial Search Engine’-4
The Conceptual Architecture
<-
6. Example6. Example
b.Prototype System-1
Geo-coding Service
Map-providing Service
6. Example6. Example
b.Prototype System-2 Software packages used
IBM Websphere UDDI Registry 1.1 VC++ 6.0
Standards SOAP 1.2 UDDI 2.0 GML 2.0
6. Example6. Example
b.Prototype System-36. Example6. Example
b.Prototype System-46. Example6. Example
b.Prototype System-56. Example6. Example
b.Prototype System-6
<-
6. Example6. Example
7. Discussion & Cooperation:
a.Would rather provide spatial data service than only data
b.Make all things(hardware,software, data, processing, etc.) as interoperable as possible
c. International cooperation in developing interoperable technology
Thank you!