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).