The significant purpose of SDI is to provide governments, organizations, and executive agencies access to basic, processed, classified, and updated spatial data at the lowest possible cost and in the shortest possible time. The goal is not that an organization should provide and own its all spatial data layers, but each organization is responsible for preparing and updating different layers of its spatial data and receives other layers of spatial data from other organizations with a specific mechanism. Each organization has a certain financial capacity to prepare or purchase the required spatial data.
Download the produced documents by National Cartographic Center and other international authorities from here
Search on information layers and existence maps in Portal of National Spatial Data Infrastructure from here
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