| In today's world, geographic data plays an increasing role in many areas, including academic research, government decision making, and in peoples everyday lives. As the quantity of geographic data gets larger, making full use of the data in a distributed, heterogeneous network environment, like the Internet, becomes a major issue. To better utilize and share those valuable resources, metadata standards have been developed. Metadata makes it easier to discover, explore, and share geographic data, particularly for cataloging geographic data in clearinghouses. But one of the new problems that emerged with metadata is interoperability since multiple metadata standards exist. Important geographic metadata standards include: ISO 19115, Dublin Core, CSDGM (US) and prENV 12657 (Europe). Semantically, metadata standards are distinct but, rather, they overlap and relate to each other in diverse and complex ways. In this dissertation, we propose a method and supporting software toolset, entitled Metadata Community Adaptor (MCA), to perform transformations between different geographic metadata standards, and help solve certain interoperability issues by using the new popular web service and XML/XSLT technologies. The distinguishing characteristic of the proposed approach consists of the unique combination of capabilities for dealing with metadata creation, metadata validation, and metadata transfer between standards. The dissertation provides details of the proposed approach and supporting software tools and includes extended descriptions of software specification and design. All the main capabilities of MCA are illustrated with the aid of four application scenarios. A feature-based comparison with related work is also included, and an outline of possible directions of future work is provided. |
