Interoperable Coordinate Transformation and Identification of Coordinate Systems

Daniel Specht

Topographic Engineering Center

Email: Daniel.L.Specht@tec02.usace.army.mil

Link to full paper

The OpenGIS Consortium (OGC), an industry group, is developing COM, CORBA, SQL and Java interface specifications to facilitate development of interoperable geospatial software. OGC established the Coordinate Transformation Working Group (CT-WG) in April 1998. The working group developed a Unified Modeling Language object model of coordinate systems and coordinate transformations in coordination with ISO TC/211. In June 1999 OGC released this object model as part of a request for proposal. By the date of this conference the CT-WG expects to have accepted interface specifications drafted in response to this proposal.

This paper describes the object model and those specifications. The object model describes a Coordinate Reference System as a collection of axes and at least one datum. The object model is available at http://www.opengis.org/techno/request.htm under “request 9.”

The specification will provide a common way of identifying coordinate systems and of accessing coordinate transformation services that supports accuracy calculation. When implemented, these specifications will ease data import. Users with compliant applications will import data without having to be aware of the coordinate system. If the application cannot import data in a given coordinate system, any compliant server will transform the coordinates to the native coordinate system.