| Author: | Gan, Wan-chung Ernesto |
| Title: | Error metadata management system : with application to Hong Kong 1:20,000 digital topographic map series |
| Degree: | M.Sc. |
| Year: | 1999 |
| Subject: | Geographic information systems -- China -- Hong Kong Metadata -- China -- Hong Kong -- Management -- Data processing Digital mapping Hong Kong Polytechnic University -- Dissertations |
| Department: | Multi-disciplinary Studies Department of Land Surveying and Geo-Informatics |
| Pages: | xiii, 143 leaves : ill. (some col.) ; 30 cm |
| Language: | English |
| Abstract: | When spatial data is collected via various data capture methods, positional accuracy of a dataset is also to be recorded separately according to the Geospatial Positioning Accuracy Standards (FGDC, 1998c) for compliance with the Content Standard for Digital Geospatial Metadata (FGDC, 1998a). A specific feature is still hard to be identified from a dataset with the CSDGM compliant metadata. Cartographic operations on the spatial data will further deteriorate its positional accuracy. When data user adopts to utilize any digital cartographic data, he/she will suffer from aggregated errors of generalization. These errors will still be unveiled in the metadata in the CSDGM format. The study presented in this thesis is to investigate and to design a metadata structure for the Hong Kong 1:20000 Topographic Map Series. An Error Metadata Management System (EMMS) is developed. Error Metadata indicates the data quality of the data in GIS. It includes quality information for spatial objects. The EMMS is developed based on JMDL from the MicroStation/J. JMDL is utilized the Sun's JAVA packages as its customized graphic packages to handle the MicroStation graphic elements. The EMMS database is stored in Microsoft Access 97 through JDBC-ODBC bridge from JAVA. Positional accuracy of a spatial object is varied with the data capture methods used. The EMMS stores accuracy information for spatial data in the metadata database, as well as the data capture method, pre-processing parameters, the data source, and the temporal information about individual spatial objects in GIS. Lineage information will be dynamically recorded whenever data manipulated. Thus, aggregation error of spatial objects through customized cartographic operations can be calculated from the database. The EMMS also provides statistical operation of RMSEs for a specific set of spatial objects for data producers to prepare CSDGM metadata according to the GPAS's requirements. Users can utilize standard deviation for error propagation in their own application. Query on currency from lineage information for data producer to update those obsolete spatial objects. The EMMS can be treated as a quality management tool for quality assurance and quality control whereas data is originated captured through less accurate method. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b14852639.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 10.98 MB | Adobe PDF | View/Open |
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