Abstract

A data model for managing dynamic datums in GIS
Track: Technology
Authors: Kevin Kelly

The International Terrestrial Reference Frame (ITRF) is rapidly becoming the coordinate system of choice for both global and national geodetic datums. ITRF control coordinates are being disseminated for use in all types of surveying, mapping and GIS applications. The reality of crustal motion combined with the adoption of ITRF and the use of GNSS for surveying measurements implies that positional coordinates of points anywhere in the world will change as a function of time. By inventorying and organizing the data required to calculate reference frame transformations and displacements, we create a GIS data model which highlights their relationships, dependencies and commonalities. Supported by such a data model software tools can be developed that operate on other geospatial data to perform desired frame transformations and displacement calculations. In this way we can track locations of even very large geospatial datasets through changes in reference frame and as global or local crustal deformation occurs.