|
|
|
The research on Metadata Management of Resource and Environment Spatial Database
Yanrong Cao, Jiantao Bi, Hongqiao Wu, Jianbang He
Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences , Beijing 100101 , P.R. China
Yuxia Huang
Institute of Remote Sensing Application , CAS , Beijing 100101 , P.R. China
The Resource and Environment Spatial Databases (RESD) have a mass of data, which is dramatically growing. But sharing of these data has to face so many problems: To manage and share data, metadata is becoming an important tool.
This paper discusses how to establish metadata management system of Resource and Environment Spatial Database.
Firstly, it develops architecture of metadata standard for the RESD, and gives the design method of Unified Modeling Language (UML) static diagram for metadata framework.
Secondly, it gives data dictionary for detail element definition. Through the dictionary, the architecture of metadata is being expressed.
And it uses extensible markup language(XML) to describe metadata. This paper gives a metadata DTD (Document Type Definition), discusses how to store XML files and how to query record from database. At last, it carries out metadata management and metadata’s expansibility.
It can help users to query effectively and find resources quickly from RESD.
1 Foreword
The RESD possess the databases of each side such as nature, society, economy and population etc crowd with the environment database. Not only the data bulk is huge, and divide the different hardware terraces of category, and possesses the structure and the content of different types by the different software supports. How solving the production, management and organization of data and sharing altogether is badly in need of the problem solved. As data producers, eagerly needs one set of effective data management and maintenance method, and the service that the same also requirement of data subscriber can be procured promptly from producer there and safety and effective and overall is so that following in resources and the environment data of magnanimity quickly and accurately find, visit, procure and use the data that need. But, how to share these information altogether on the network, and still existing several problems:
-
The data are in a single day shared on the network altogether, and involve the problem of copyright;
- Before users of data require to use, firstly will understand his content of the spatial data of
requirement , cover , quality , management, data producer, the method providing ,concerned information etc .
- For network speed, user does not have the metadata and directly downloads. It will waste time in the download.
Spatial metadata provide the settlement that the information was served to the whole problem and have provided a feasible method.
Generally thinks that the effect in the course studied the metadata in the spatial data warehouse to enjoy altogether must be started with from three aspects : 1 ) the standard of metadata ( Profile ) ;2 ) the metadata management system ( Spatial Metadata Management System, SMMS ) ;3 ) the information service that takes the metadata as the foundation to provide .
Stressing here discusses preceding two the problems , namely problem of metadata management aspect.
The geographical information metadata standard versions that has consulted and follow ISO/TC211 final is submitted to, as well as after the real requirement inside this item, the research group ( Research Group On Geographic Information Sharing, RGIS ) work carried on the space metadata standard of development item .Firstly, the design has been in progress to the structure of metadata by the general model building language UML of use , and has added with the corresponding metadata data dictionary , and has formed the standard that meets with ISO/TC211.Secondly, we have used XML and JAVA development tool of industry standard to develop the metadata management system on Internet of operating at the aspect of the establishment of software .
|
|
|