39. Appendix B: Glossary¶
A “coordinate reference system”. The combination of a geographic coordinate system and a projected coordinate system.
Geospatial Data Abstraction Library, pronounced “GOO-duhl”, an open source raster access library with support for a large number of formats, used widely in both open source and proprietary software.
Geographic information system or geographical information system captures, stores, analyzes, manages, and presents data that is linked to location.
“JavaServer Page Template Library”, a tag library for JSP that encapsulates many of the standard functions handled in JSP (database queries, iteration, conditionals) into a terse syntax.
“JavaServer Pages” a scripting system for Java server applications that allows the interleaving of markup and Java procedural code.
“Keyhole Markup Language”, the spatial XML format used by Google Earth. Google Earth was originally written by a company named “Keyhole”, hence the (now obscure) reference in the name.
The Open Geospatial Consortium (OGC) is a standards organization that develops specifications for geospatial services.
The Open Source Geospatial Foundation (OSGeo) is a non-profit foundation dedicated to the promotion and support of open source geospatial software.
“Spatial reference ID” a unique number assigned to a particular “coordinate reference system”. The PostGIS table spatial_ref_sys contains a large collection of well-known srid values and text representations of the coordinate reference systems.
“Structured query language” is the standard means for querying relational databases.
SQL Multimedia; includes several sections on extended types, including a substantial section on spatial types.
“Scalable vector graphics” is a family of specifications of an XML-based file format for describing two-dimensional vector graphics, both static and dynamic (i.e. interactive or animated).
“Well-known binary”. Refers to the binary representation of geometries described in the Simple Features for SQL specification (SFSQL).
“Well-known text”. Can refer either to the text representation of geometries, with strings starting “POINT”, “LINESTRING”, “POLYGON”, etc. Or can refer to the text representation of a CRS, with strings starting “PROJCS”, “GEOGCS”, etc. Well-known text representations are OGC standards, but do not have their own specification documents. The first descriptions of WKT (for geometries and for CRS) appeared in the SFSQL 1.0 specification.