  This article explores the design and construction of a geo-spatial Internet
web service application from the host web site perspective and from the
perspective of an application using the web service. The TerraService.NET web
service was added to the popular TerraServer database and web site with no
major structural changes to the database. The article discusses web service
design, implementation, and deployment concepts and design guidelines. Web
services enable applications that aggregate and interact with information and
resources from Internet-scale distributed servers. The article presents the
design of two USDA applications that interoperate with database and web service
resources in Fort Collins Colorado and the TerraService web service located in
Tukwila Washington.
