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INSROP GIS Database

The database module organises and stores INSROP data for retrieval and analysis. This involves both storage of structural data (i.e., actual data) and descriptive data (i.e., metadata). A prime objective for organising data from several sources into a database is to make it available to users other than the original data supplier. To support this objective, it is equally important to include information about the data set. The INSROP GIS metadata should provide documentation on each INSROP GIS data set.

Core Database

Although INSROP GIS may utilise data sets from any location a disk, all INSROP GIS data sets are organised in sub-directories of the DATABASE folder, which again is a sub-directory of the main INSROP GIS folder (i.e. G:\INSROP_GIS). The DATABASE sub-directories include information themes which was originally created with 8-character abbreviated names, e.g. BASECART for Base Cartographic data, to comply with current DOS restrictions. The individual base cartographic data sets are stored as sub-directories below the BASECART directory. E.g., the special INSROP extracts of the Digital Chart of the World in 1:1 mill. is found as ARC/INFO coverages in the G:\INSROP_GIS \DATABASE\ BASECART\DCW_1 folder. However, this storage structure is primarily only important for system development or updates. On the INSROP GIS CD, the data are stored in the proper location, and INSROP GIS enables access to the data by selecting the requested information theme from a menu providing proper descriptive names (e.g. Base Cartography). See also Use data sets from the INSROP GIS database.

Note: The menu choice Create database listing ASCII file in the Projects window will list the entire contents of an INSROP GIS database to an ASCII file.

Metadata

Data stored within a GIS are inherently complex. Data sets may be defined by a variety of parameters from data structures (e.g. raster, vector, triangulated irregular networks, etc.) to geographic environments (e.g. spheroid, datum, projection, co-ordinate system, etc.) to sources and processing procedures (e.g. remotely sensed, rectified, classified, digitised, etc.). Consequently, there must be an organised method available to store, query, and retrieve information. Therefore, it is the role of metadata to provide the GIS user with documented information describing basic data characteristics and allow for the assessment of GIS data sets within the core database. For example, once a metadata database has been established the information can support user interface applications by providing documentation on data sets. Also, the metadata database serves a strategic role in supporting the GIS database by providing the capability to assess data quality, determine missing or suspect information, and survey the history of processing steps (i.e., lineage) associated with the GIS data.

The documentation of an INSROP GIS data set shall provide a user with enough information to enable a decision of whether the data set suits the users needs and satisfy the users requirements. The documentation standard chosen for INSROP GIS data sets is a modified version of the documentation layout that are used for the ArcView Sample Data (see Guide to ArcView Sample Data in the online ArcView Help documentation).