Spatial data infrastructure (SDI) is generally defined as the technologies, policies, and people necessary to promote sharing of geospatial data throughout all levels of government, the private and non-profit sectors, and the academic community. Goal of SDI is to reduce duplication of effort among agencies, improve quality and reduce costs related to geographic information, to make geographic data more accessible to the public, to increase the benefits of using available data, and to establish key partnerships with states, counties, cities, tribal nations, academia and the private sector to increase data availability.
With efforts of previous years, datasets of various types have been produced at global, national, regional, city level. Recently much demands on service and application of SDI have been raised and much attention has been paid to data updating, data harmonization, and geo-spatial cyberinfrastructure that aims at solving the problem of efficiently connecting data, computers, and people over the Internet.