In using spatial data, such as maps in raster or vector format in GIS environment, spatial databases, or when downloading data through a web-service, we often don't know or are not sure who collected the data and when they did it, what the quality of the data is, what coordinate reference system the data are in, what version the data format is or other information on data that allow to be used and interpreted.
Such data and their application (e.g. products and services based on them) have a lower value. To avoid these problems, metadata are collected. Metadata are integral part of data and together they make single units. Metadata need to be collected during the collection of data and they need to be updated when data are changed. In other words, important actions related to data have to be documented through metadata. NSDI metadata are elaborated in NSDI Metadata Specification v. 2.0.
These web sites offer an insight into the metadata of the National Spatial Data Infrastructure (NSDI). These pages have an informative character and are used for the exchange of knowledge. They are also giving metadata editors support in collecting and documenting metadata. Special attention was devoted to explanations and examples documenting each metadata element.
The scope of these sites gives insight into compliance of the NSDI metadata with other metadata systems such as INSPIRE and ISO/TC211. Using given examples of XML coding, XPath variables and other elements support to the development of other editors and metadata systems is given. That is needed because different scientific fields, branches and professions need specialized metadata systems about their data sources.
Croatian SDI has to fulfill national needs, but also to connect Croatian SDI with EU INSPIRE SDI. Therefore, NSDI metadata comply with the requirements of EU INfrastructure for SPatial Information (INSPIRE) metadata.