ABSTRACT
Using the Global Spatial Data Model (GSDM) is primarily a matter of choosing to do so. Although the GSDM contains no new science, it does represent a different way of organizing and storing spatial data. The intent in defining the GSDM was to begin with the assumption of a single origin for 3-D data and, from that, to build a collection of procedures that can be used to handle 3-D spatial data more efficiently. The GSDM competently handles 3-D data with large standard deviations just as well as it handles data with small standard deviations. The actual transition to using the GSDM will vary among persons and organizations. The GSDM has two primary features—the functional model and the stochastic model. Because geospatial data are connected to the Earth and because spatial data are 3-D, the “big picture” geometrical relationships included in the GSDM involve a lot of geometrical geodesy.
