The NGDF Gateway will provide access to a wide variety of spatially related data owned by public and private sector data providers. This data could include anything from topographical or geological maps to statistical information such as that from the census and health service.
The Gateway will enable searches to be carried out through both centrally held and distributed information (metadata) about the datasets, held either by the data producers themselves or by intermediary service providers. This metadata will include details about the data such as who the supplier is, what the geographical extent is, when the data was last updated, what the supply formats are etc.
The user of the Gateway will be able to carry out keyword searches over the Internet to locate all of the datasets relating to that key word. The service will do this by searching for the keyword in the metadata held for each of the datasets. Alternatively the user will be able to carry out searches based on geographical extent. For example the user would define an area of interest on a map of UK and the service would locate all datasets which hold information about that defined area.
Data providers will be provided with guidance on metadata content (NGDF metadata guidelines) and encouraged to describe their data using these. This will mean that key word searches across the Internet will provide the best results possible.
The metadata produced by the data providers will be quality assured, initially at a basic level to validate that the information conforms to the NGDF metadata guidelines, but in the longer term the quality of the actual information itself will also be quality assured.
As well as enabling users to find out what data is available, the NGDF Management Board will also be enabling the establishment of a help desk which will provide data providers with help preparing their metadata data, setting up maintenance procedures and guidance on establishing their own metadata services.
The NGDF Metadata Gateway Architecture and Implementation document provides a more complete description of the proposed Metadata Service.