Building the Visual Earth

Over the past several years there has been a broad effort towards realizing the Digital Earth, which involves the digitization of all earth-related data and the organization of these data into common repositories for wide access. Recently the idea has been proposed to go beyond these first steps and produce a Visual Earth, where a main goal is a comprehensive visual query and data exploration system. Such a system could significantly widen access to Digital Earth data and improve its use. It could provide a common framework and a common picture for the disparate types of data available now and contemplated in the future. In particular much future data will stream in continuously from a variety of ubiquitous, online sensors, such as weather sensors, traffic sensors, pollution gauges, and many others. The Visual Earth will be especially suited to the organization and display of these dynamic data. This paper lays the foundation and discusses first efforts towards building the Visual Earth. It shows that the goal of interactive visualization requires consideration of the whole process including data organization, query, preparation for rendering, and display. Indeed, visual query offers a set of guiding principles for the integrated organization, retrieval, and presentation of all types of geospatial data. These include terrain elevation and imagery data, buildings and urban models, maps and geographic information, geologic features, land cover and vegetation, dynamic atmospheric phenomena, and other types of data.