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Supporting Metadata and Coordinate Systems for Scientific Data in the Horizon Java Package

Raymond L. Plante
National Center for Supercomputing Applications
University of Illinois
405 North Mathews Ave.
Urbana, IL 61801, USA
horizon@ncsa.uiuc.edu

Abstract:

When exploring scientific data with a data visualization tool, scientists are usually more interested where the data resides in physical or conceptual space than its position within some data array. Such a space, the data's domain, is often referred to as the data's World Coordinate System. This document describes how the Horizon Image Browser Java Package supports the mapping between a datum's position in a dataset and its position within its World Coordinate System. Because the parameters describing a coordinate system can be considered as metadata of the system, this document presents the support for world coordinates as a case study in the use of metadata within Horizon, beginning with a general description of Horizon's metadata model. This model allows data objects to conveniently carry with them a description of its data, allowing other objects to properly interpret the data. In the case of world coordinate systems, a world coordinate system object can therefore know how to determine a datum's coordinate position and even display that position in its conventional, application-specific format.





Ray Plante
Mon Aug 25 15:16:12 CDT 1997