Science gateways are a key driver of the democratization of access to computing and data resources in science and engineering research. Science gateway technology has evolved in tandem with modern web technologies and adopts several standard design principles that have accelerated their development. The evolution of science gateways and their most common components are discussed, followed by some examples of popular gateways adopted by the GIS community. The challenges faced by modern gateways in response to user needs and evolving technologies are presented to drive further discussion and development.
Spatial data infrastructure (SDI) is the infrastructure that facilitates the discovery, access, management, distribution, reuse, and preservation of digital geospatial resources. These resources may include maps, data, geospatial services, and tools. As cyberinfrastructures, SDIs are similar to other infrastructures, such as water supplies and transportation networks, since they play fundamental roles in many aspects of the society. These roles have become even more significant in today’s big data age, when a large volume of geospatial data and Web services are available. From a technological perspective, SDIs mainly consist of data, hardware, and software. However, a truly functional SDI also needs the efforts of people, supports from organizations, government policies, data and software standards, and many others. In this chapter, we will present the concepts and values of SDIs, as well as a brief history of SDI development in the U.S. We will also discuss the components of a typical SDI, and will specifically focus on three key components: geoportals, metadata, and search functions. Examples of the existing SDI implementations will also be discussed.