Technologies and Standards on Spatial Data Sharing in China

  Jianya Gong

Wuhan University, CHINA

Contents

1. Introduction in Geo-Information Communities in China

2. The Researches for Geo-spatial Data Sharing Technologies and Standards

3. Implementation and Test of Geographic Information Sharing Standards

4. Conclusions

1. Introduction of Geo-Information Communities in China

Status of Geospatial Information Technology in China

• Chinese government encourages development on Geospatial Information Technology

• The technologies of Geospatial Information in China have developed quickly in recent years, especially on :– Remote Sensors– Satellite Navigation System– Digital Photogrammetry and Remote Sensing Image

Processing System– GIS Software System – Remote Sensing and GIS Application

Photogrammetry, Remote Sensing and GIS System in China

• Digital Photogrammetry System

• Remote Sensing Processing System

• GIS Software System

Two commercial digital photogrammetry systems

• VirtuoZo

is developed by Wuhan University and Super Company

• Jx-4

is developed by Chinese Academy in Surveying and Mapping, and Beijing Siwei Company

They occupy 80-90% markets in China

Four remote sensing processing systems

• GeoImager is developed by Wuhan University and Wuda Geo Company

• RSImages is developed by Chinese Academy in Surveying and Mapping,

• Taitan Image System is developed by Beijing Taitan Company

• RS System is developed by Institute of Remote Sensing Application of Chines

e Academy

They occupy 20-30% markets in China

Three commercial GIS software systems in China

They occupy about 50% markets in China

•GeoStar

is developed by Wuhan University and Wuda Geo Company

•MapGIS

is developed by Chinese Geology University and Zhongdi Company

•SuperMap

is developed by Institute in Resource and Geography of Chinese

Academy and SuperMap Company

2. Research on Geo-spatial Data Sharing Technologies and Standards

Research Funding

• From National High Technology Program (863 program): a specific research field “Earth Observation and Navigation”. The technologies and standards on spatial data sharing have been as a key project

• From State Bureau of Surveying and Mapping

• From other agencies: Local government, Geo-related companies

Research Projects and Plans

• 863 key project: “Standards of Geo-Spatial Data Sharing and Technologies of Geo-Information Web Service” (2002-2005).

• Ongoing national standards: GML, WFS, WMS, Data Transfer Standard, Spatial Scheme, GI Registration, Catalogue service, etc.

• 863 key project: “Technologies of GRID-GIS” (2007-2010). The interoperability technologies standards will be one of the important contents.

• More standards will be upcoming in the near future.

Three levels of spatial data sharing standards in China

Basic Standards

Geospatial Data Distribution Standards

Geospatial Data Interoperability Standards

Level 1: Basic Standards

• Metadata Standard: adoption of ISO 19115 and released in last few years

• Geospatial Feature Classification: proposed by China’s institutes, released in 1992 and updated in 2005

• Geospatial Data Transfer Standard: proposed by Wuhan University, released in 1999 and updated in 2006

• Geospatial Data Model: adoption of ISO 19107 and to be released in 2008

• Geospatial Visualization and Symbolization Standard: proposed by Wuhan University and to be released in 2008

• Geography Markup Language (GML): adoption of ISO 19136 and to be released in 2008

Geo-spatial Data Transfer Standard

Contents:

（ 1 ） Basic information of data set

（ 2 ） Definition of feature types

（ 3 ） Data structure of attribute data

（ 4 ） Geometric data

（ 5 ） Annotation data

（ 6 ） Topology data

（ 7 ） Attribute data

（ 8 ） Visualization data

•adopting geo-spatial data model•using both BNF and XML encoding

1++

1++1++

2++1++

Spatial DB

Spatial Object Image DEM

Graphics attribute

Point Curve Surf. Assemble Objects

Line String Polygon Multi-surf. Multi-poly.Multi-curve

Multi LineStringMultiple PolygonLinearitySegment

Solid

Geospatial Data Model

HeadBegin<CR>DataMark: CNSDTF-VCT<CR>Version: <GB/T17798-2007><CR>[CoordinateSystemType: C|D|P<CR>][Dim: <2|3><CR>][XAxisDirection: <E|N|W|S><CR>][YAxisDirection: <N|E|S|W><CR>][XYUnit: M|D|< 其他单位 ><CR>][ZUnit: M|< 其他单位 ><CR>][Spheroid: < 参考椭球 ><CR>][PrimeMeridian: < 首子午线 ><CR>][Projection: < 投影类型 ><CR>][Parameters: < 投影参数 ><CR>][VerticalDatum: < 高程基准 ><CR>][TemporalReferenceSystem: < 时间参照系 ><CR>

][ExtentMin:< 坐标 ><CR>][ExtentMax:< 坐标 ><CR>][MapScale: < 整数 ><CR>][Offset: < 坐标 ><CR>][Date: < 日期 ><CR>][Separator: < 字符 ><CR>]HeadEnd<CR>

Basic information of data set (using BNF)

要素类型参数内容和格式<要素类型参数 > ::=

FeatureCodeBegin<CR>{<要素类型编码 >,<要素类型名称 >,<几何类型 >,<属性表名 >{,<用户项 >}<C

R>}FeatureCodeEnd<CR>

<要素类型名称 > ::= <字符串 ><字符串 >中不能含有逗号 (,)。

<几何类型 > ::= Point | Line | Polygon | Solid | Collection | Annotation <属性表名 > ::= <标识符 >空表名表示没有属性表。<用户项 > ::= <字符串 >

<字符串 >中不能含有逗号 (,)。

Definition of feature types

(using BNF)

<?xml version="1.0" encoding="UTF-8"?><schema targetNamespace="http://www.csdf.org/Schema" xmlns:csdf="http://www.csdf.org/Schema" xmlns="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified">

<complexType name="datasetType"><annotation>

<documentation>分为矢量数据集、影像数据集和格网数据集 </documentation></annotation><choice>

<element ref="csdf:vectorData"/><element ref="csdf:imageData"/><element ref="csdf:gridData"/>

</choice></complexType><element name="dataset" type="csdf:datasetType">

<annotation><documentation>所有数据实例必须以该元素作为根元素。 </documentation>

</annotation></element><complexType name="vectorDataType">

<annotation><documentation>矢量数据类型 </documentation>

</annotation><sequence>

<element ref="csdf:vectorMetaData"/><element ref="csdf:featureCodes"/><element ref="csdf:tableStructures"/><element ref="csdf:pointFeatures" minOccurs="0"/><element ref="csdf:curveFeatures" minOccurs="0"/><element ref="csdf:polygonFeatures" minOccurs="0"/><element ref="csdf:solidFeatures" minOccurs="0"/><element ref="csdf:multiGeometryFeatures" minOccurs="0"/><element ref="csdf:annotationFeatures" minOccurs="0"/><element ref="csdf:topoNodes" minOccurs="0"/><element ref="csdf:topoEdges" minOccurs="0"/><element ref="csdf:attributeTables" minOccurs="0"/><element ref="csdf:varchars" minOccurs="0"/><element ref="csdf:styles" minOccurs="0"/>

</sequence></complexType><element name="vectorData" type="csdf:vectorDataType">

<annotation><documentation>矢量数据 </documentation>

</annotation></element><complexType name="vectorMetaDataType">

<annotation><documentation>矢量数据元数据类型 </documentation>

</annotation><sequence>

<element name="version" type="string" fixed="GB/T17798-2007">

Basic information for data set

(using XML)

<simpleType name="geometryTypeType"><annotation>

<documentation>几何类型 </documentation></annotation><restriction base="string">

<enumeration value="Point"/><enumeration value="Line"/><enumeration value="Polygon"/><enumeration value="Annotation"/><enumeration value="Solid"/>

</restriction></simpleType><complexType name="featureCodeType">

<annotation><documentation>要素类型参数类型 </documentation>

</annotation><sequence>

<element name="code" type="string"><annotation>

<documentation>要素类型编码 </documentation></annotation>

</element><element name="name" type="string">

<annotation><documentation>要素类型名称 </documentation>

</annotation></element><element name="geometryType" type="csdf:geometryTypeTyp

e"><annotation>

<documentation>几何类型 </documentation></annotation>

</element>

Definition of feature types

(using

XML)

Level 2:Geospatial Data Distribution Standards

• Specification of geospatial dataset registration registration

• Specification of geospatial data catalogue

• Guide of geospatial data distribution

Specification of geospatial dataset registrationregistration

was proposed by National Information Center with reference to ISO 19135 “Procedures for reProcedures for registration of geographic information items”gistration of geographic information items” and W3C UDDI/WSDL, and will be released in 2008.

Example: Registration service system for geo-spatial dataset

Specification of geospatial data catalogue

• With reference to OGC catalogue service specification, and to be released in 2008.

Example: Catalogue Service for Geospatial Data

Results of the catalogue service example

Guide of Geospatial Data Distribution

• was proposed by Chinese Geomatric Center, and applied in geospatial data distribution.

Example: Distribution service system for geospatial data

Level 3: Geospatial Data Interoperability Standards

• Simple Feature Implementation Specification – for OLE/COM– for JAVA

• Web Map Service (WMS), Web Feature Service (WFS), Web Coverage Service (WCS)– adoption of the corresponding ISO or OGC standards

and to be released in 2008

Simple Feature Implementation Specification for OLE/COM

• Simple feature implementation specification for OLE/COM from OGC, has been implemented and tested by Chinese GIS software.

GeoSurfSystem

DEM System Image DB System

2-D GIS Application System

DE

M C

OM

Image C

OM

2-D

GIS

C

OM

3-D

GIS

C

OM

Oth

er CO

M

ActiveX

3-D GIS

Editing

Query and analysis COM

Query Analysis Mapping

Spatial Data operation Interface (OGC specification)

DB2 SyBase Oracle ARC/SDE Informix GeoStarfile

CO

M/

DC

OM

VectorImage DEM

SD

C/

OD

BC

DEM Ana

IGeometry

IUnknown

IPoint

ILintString

IPolygon

IGeoAnnotation

IGeometryCollection

IMultiPoint

IMultiLineString

IMultiPolygon

Objects

Common Methods IGeometry

IGeometry::get_Dimension

IGeometry::get_SpatialReference

IGeometry::put_SpatialReference

IGeometry::IsEmpty

IGeometry::SetEmpty

IGeometry::IsSimple

IGeometry::get_Envelope

IGeometry::Clone

IGeometry::Project

interface IGeometry : IUnknown

interface IPoint : IGeometry

interface ILineString : IGeometry

interface IPolygon : IGeometry

interface IGeoAnnotation : IGeometry

interface IGeometryCollection : IGeometry

interface IMultiPoint : IGeometryCollection

interface IMultiLineString : IGeometryCollection

interface IMultiPolygon : IGeometryCollection

Common MethodsCommon Methods

Example of geographical information sharing between different data sources (Implemented in Geostar)

Simple Feature Implementation Specification for JAVA

• Simple feature implementation specification for JAVA has been proposed with referencing to Simple feature implementation specification for CORBAR, has been implemented and tested.

3. Implementation and Test of Geographic Information Sharing Standards

Several GIS software systems in China have implemented the standards on geospatial data sharing, such as CNSDTF, simple feature implementation specification for COM, for JAVA, and WMS, WFS, WCS and so on.

Test of Web Map Service

Test of Web Coverage Service

Test of Web Feature Service

Geo-spatial data integration by multiple GISs based on geo-spatial information w

eb service specifications

Spatial Data Integration

GeoStar

ArcIMS

SuperMap MapGIS

MapInfo

Example: spatial data integration by multiple web service specifications

Data Integration from Multi Systems and Based on Multi Specifications

Conclusions• China has been doing research, implementation and

testing on geo-spatial data sharing standards

• Metadata standard, geospatial feature classification and geospatial data transfer standard have been released and applied in China.

• Geospatial registration service, catalogue service, GML, WMS, WFS, WCS will be released in the near future.

• The research and application of geo-spatial data sharing standards in China are still in the primary stage, and we hope to have more cooperation with the colleagues in the world.

Thank You!