Simple feature access

Simple feature access (SFA; also called ISO 19125), is both an OpenGIS and ISO Standard that specifies a common storage model of geographical data (point, line, polygon, multi-point, multi-line, etc.) using well-known text (or binary). The geometries are also associated with spatial reference systems. The SFA also specifies attributes, methods and assertions with the geometries.

In general, a 2D geometry is simple if it contains no self-intersection. The SFA specification defines DE-9IM spatial predicates and several spatial operators that can be used to generate new geometries from existing geometries.

See also

• SQL/MM Spatial a similar standard

External links

• OpenGIS Specifications (Standards)
• OpenGIS Simple Features Specification for CORBA (99-054)
• OpenGIS Simple Features Specification for OLE/COM (99-050)
• OpenGIS Simple Features Specification for SQL (99-054, 05-134, 06-104r3)
• OGR - OGR library which implements relevant OGC standards
• OpenGIS Simple Features Specifications For SQL
• MySQL 5.1 documentation on Spatial extensions
• PostGIS Simple Features implementation for PostgreSQL