HR: 08:45h
AN: U31D-04    [Abstracts]
TI: Space Age Geodesy: Global Earth Observations of Ever Improving resolution and Accuracy
AU: * Carter, W E
EM: bcarter@ce.ufl.edu
AF: University of Florida, Department of Civil and Coastal Engineeering 365 Weil Hall, Gainesville, FL 32611, United States
AB: The launch of Sputnik-I by the USSR in 1957, and the resulting competitive US-USSR space exploration and weapons programs, led to the need for global geodetic measurements of unprecedented accuracy, and the means to develop new observing techniques to meet those needs. By the 1970s the geodetic community developed very long baseline interferometry (VLBI), lunar laser ranging (LLR), and satellite laser ranging (SLR), and launched international tests that led to the establishment of the International Earth Rotation Service (IERS). Today the IERS provides a stable International Celestial Reference Frame (ICRF), and accurate earth orientation parameters (EOP) values, using a combination of VLBI, LLR, SLR, and the Global Positioning System (GPS). There are hundreds of continuously operating GPS stations around the world, providing centimeter station locations and millimeter per year station velocities, in the International Terrestrial Reference Frame (ITRF). The location of any point on earth can be determined relative to the ITRF to within a few centimeters from a few days of GPS observations, and using kinematic GPS, the positions of moving objects can be tracked to a few centimeters at distances of tens of kilometers from the nearest GPS ground stations. This geodetic infrastructure and space age technology has led to the development of new airborne topographic mapping techniques, most significantly, airborne laser swath mapping (ALSM). With ALSM, it is now possible to map thousands of square kilometers of terrain with sub-decimeter vertical accuracy in hours. For example, the entire length of the San Andreas fault, in California, was mapped in a few hundred hours of flying time. Within the next few decades, global ALSM observations will make it possible for scientists to immediately access (by the internet) data bases containing the locations (cm accuracy) and rates of motion (mm per year accuracy) of points on the surface of earth, with sub-meter spatial resolution, for any area of interest. Digital elevation models (DEMs) and other products derived from ALSM observations are already revolutionizing such diverse fields of research as hydrology, geomorphology and earth surface dynamics, neotectonics, and coastal dynamics. Expanding the coverage of and access to ALSM observations can only lead to new scientific findings about our ever changing planet Earth.
DE: 1229 Reference systems
DE: 1294 Instruments and techniques
DE: 1299 General or miscellaneous (1709)
DE: 1625 Geomorphology and weathering (0790, 1824, 1825, 1826, 1886)
DE: 1794 Instruments and techniques
SC: Union [U]
MN: 2007 Fall Meeting