Extending WSDL for describing complex geodata in GIS service

Web Services Description Language (WSDL) is an XML-based specification for describing the functionalities provided by web services [1], and widely-adopted in the IT industry. However, the message types defined in WSDL for interoperation are insufficient when describe complex data (such as, geodata) by using conventional data types in many application scenarios. For example, geodata (such as, a digital image captured through remote sensing technologies) is usually described and located simply as an URL string. Since important metadata information for description and verification are missing, neither providers nor users have good experiences with the current GIServices described in WSDL. In this paper, we extend the WSDL specification to support description of complex geodata. This extended WSDL is more pragmatic and effective than the standard WSDL in GIService-specific scenarios.