Web Service for extracting Terrain Openness from DEM Data

This paper discusses the implementation of the terrain openness parameter as a Web Service. Terrain Openness is a new morphology parameter that emphasizes surface concavities and convexities (Yokoyama et al., 2002) and can be derived directly from a digital elevation model (DEM). It is essentially an angular measure of the relation between surface relief and horizontal distance and can be used as a proxy for topographic curvature. It is not sensitive to noise in the data and has spatial scale built in its definition. However, the Terrain Openness parameter has not been widely used, perhaps because of limited software availability. Implementing it as a Web Service will ensure widest possible accessibility, because the only requirement for the user is an Internet connection and a standard web browser. This is made possible with recent advances in Service-Oriented Architecture (SOA), geospatial Web Services, and interoperability technologies. It is implemented within the framework of GeoBrain, an open, interoperable, distributed, standard-compliant, multi-tier web-based geospatial information services and knowledge building system.