干旱区生态环境知识资源中心

Since the Web Services has been widely applied in the field of GIS, geospatial information service, as a new form of GIS, is becoming more and more popular. Metadata plays a significant role in the process of description, registry and query of the geospatial information service. The metadata of the service should include adequate information, such as the functionality, price, and other quality information about the service and so on. In most cases, there are more or less geospatial information services with homologous or similar functionalities, and then the quality of service turns to be the absolutely necessary and decisive factor when selecting service. Despite the increasing importance of quality information, it is still lack of reliable and accurate method to obtain the quality information of the geospatial information service.

The study on quality of geospatial information service (QoGIS) has just started for a few years, whereas there are many results which can be used as a reference in broader field, such as the Web Services Quality Factors (WS-QF) issued by the OASIS. Quality factors refer to a group of items that uses for representing and valuing the quality of Web services. WS-QF describes a complete set of quality factors for Web Service, which can be applied to all geospatial information services by means of modification. The factor set of the WS-QF must be modified before being used to evaluate the quality of geospatial information service due to the inherent characteristic of spatial information. The modifications of the factor set include two forms: specialization and addition. Since some international standard organizations, such as the OGC, have published several standards and specifications, we can specialize the factor set by referring to the WMS, WFS, and WCS of the OGC. After these modifications, the quality factor set will be much more suitable for QoGIS. The first half of this paper will briefly introduce the WS-QF and in the later half the main content is about how to make the WS-QF more suitable for the application of geospatial information service. The fundamental idea of this paper is that it will be much easier to specialize in QoGIS in the basis of QoS rather than to rebuild a model or system.