Microsoft TerraServer: A Spatial Data Warehouse

Abstract

The TerraServer stores aerial, satellite, and topographic images of the earth in a SQL database available via the Internet. It is the world's largest online atlas, combining five terabytes of image data from the United States Geological Survey (USGS) and SPIN-2. This report describes the system-redesign based on our experience over the last year. It also reports usage and operations results over the last year -- over 2 billion web hits and over 20 Terabytes of imagry served over the Internet. Internet browsers provide intuitive spatial and text interfaces to the data. Users need no special hardware, software, or knowledge to locate and browse imagery. This paper describes how terabytes of "Internet unfriendly" geo-spatial images were scrubbed and edited into hundreds of millions of "Internet friendly" image tiles and loaded into a SQL data warehouse. Microsoft TerraServer demonstrates that general-purpose relational database technology can manage large scale image repositories, and shows that web browsers can be a good geospatial image presentation system.