HR: 09:00h
AN: G41A-05 INVITED    [Abstracts]
TI: The Origin and Scale of the Terrestrial Reference Frame From Laser Ranging
AU: * Pavlis, E C
EM: epavlis@umbc.edu
AF: Joint Center for Earth Systems Technology (JCET), University of Maryland, Baltimore County, 1000 Hilltop Circle, Acad IV A 114E, Baltimore, MD 21250, United States
AB: The International Terrestrial Reference Frame (ITRF) provides the foundation for most of the space- and ground- based Earth observations of global change. A reference frame needs by definition to exhibit high accuracy and stability over extended periods of time. Space geodesy is the prime group supporting the establishment and maintenance of the ITRF for decades now. Through various techniques over the years, it strives to maintain continuity, improved accuracy and ever-increasing stability in the updated realizations of the International Terrestrial Reference System that also undergoes refinements over the decades. Most of these refinements are the direct result of our improved understanding of the Earth system and the continuous and complex interactions of its components. This quest for higher accuracy and stability requires the close collaboration of space geodesy with all other scientific disciplines that study and monitor the Earth system components. As we gain improved understanding of these components, space geodesy adjusts its underlying modeling of the system to better and more completely describe it. This in turn results in an improved geodetic product (ITRF) for the scientific community and all other users. Laser Ranging (LR) supports this process since the very first years of space geodesy. With the proliferation of space techniques, LR and Satellite Laser Ranging (SLR) in particular, focused on the unique strength of the technique, in providing unbiased and very precise observations of the origin and scale of the ITRF. Origin and scale stability are fundamental in determining vital global change parameters, such as mean sea level changes, Earth rotation variations, and mass redistribution amongst the components of the Earth system. SLR has contributed the most accurate observations yet, demonstrating few-millimeter level accuracy for weekly averages over the past decade. Considering the goals of ongoing international efforts such as GEO, the Global Earth Observation, the level of accuracy of the ITRF in the very near future must be significantly improved (<1mm and 0.1 mm/y). Additionally, all of the observed inconsistencies between the contributing techniques must be resolved and reconciled. We examine some of the current practice in SLR data analysis and discuss the possible improvements in the areas that have the most serious and direct effect on the development of the ITRF in light of future improvements of the ground segment, target design, and satellite missions.
DE: 1218 Mass balance (0762, 1223, 1631, 1836, 1843, 3010, 3322, 4532)
DE: 1225 Global change from geodesy (1222, 1622, 1630, 1641, 1645, 4556)
DE: 1229 Reference systems
DE: 1240 Satellite geodesy: results (6929, 7215, 7230, 7240)
DE: 1295 Integrations of techniques
SC: Geodesy [G]
MN: 2007 Fall Meeting