Spatial Data Infrastructure
Spatial data infrastructure (SDI) ensures that geographically references data held by public authorities, i.e. national spatial data, are available and reliable.
In order to achieve availability and reliability, we need data, technologies, legal regulation and mutual agreements. Thus, SDI is much more than simply a database or geographic information system.
Spatial data is data that identifies the geographic location of features and boundaries on Earth. Such features are e.g. buildings, roads, fields, forests, protected areas, cadastral parcels, lighthouses, etc. As a rule, these data are depicted on map, i.e. they are used for map production.
There are many national databases in Estonia that contain spatial data: Estonian topographic database, cadastral register, register of construction works, register of roads, environmental register, address data system, etc. It is extremely important that these spatial data are of high quality, well described and easily discovered.
In order to be able to search, discover and use spatial data from different databases, we need technologies that enable us to do so. SDI technology consists of hardware, i.e. powerful servers and other appropriate equipment, and software to create services through which spatial data are made available.
Regulation and agreements
The objective of SDI will be achieved when the interoperability of different spatial data generates a considerable added value. It means that the provided data and services must conform to certain standards. Spatial data must be unambiguous, i.e. semantically described; they must contain metadata with a common structure.
All the above is regulated in the world and also in Estonia with different regulations starting from laws and ending with recommendations, cooperation agreements and guidelines. In Estonia this field is regulated by the Spatial Data Act and Public Information Act, Implementing Rules of the INSPIRE Directive and different regulations, development plans and framework documents.