HR: 1340h
AN: G53A-0113    [Abstracts]
TI: Effect of reference stations on continuous GPS (CGPS) time series
AU: * Sella, G F
EM: sella@earth.northwestern.edu
AF: Northwestern University, 1850 Campus Drive, Evanston, IL 60208 United States
AU: Malservisi, R
EM: rmalservisi@rsmas.miami.edu
AF: RSMAS-MGG, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149 United States
AU: Wdowinski, S
EM: shimonw@rsmas.miami.edu
AF: RSMAS-MGG, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149 United States
AU: Dixon, T
EM: tdixon@rsmas.miami.edu
AF: RSMAS-MGG, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149 United States
AU: LaFemina, P
EM: plafemina@rsmas.miami.edu
AF: RSMAS-MGG, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149 United States
AB: Time series of CGPS sites in the ITRF2000 reference frame show a significant "bump" in late 2002. The time series suggest that the position of the GPS monument has moved significantly compared to the expected steady velocity prediction. Although the change has only a slight effect on computed velocities for long time series, it may introduce a significant bias in the computed velocity for shorter time series and in time series only using data collected during episodic GPS campaigns. The "bump" is easily recognized in North American sites but can also be observed in sites around the world, indicating a global effect. It is also present in time series produced by different analysis groups with different software packages (GIPSY-OASIS, GAMIT). We propose that the bump is related to "misbehavior" of one or more references sites used to transform raw GPS positions into ITRF2000. The "bump" appears to coincide with discontinuity in the operation of some reference stations. We also find that daily positions estimates are particularly sensitive to the behavior of some reference stations.
DE: 1229 Reference systems
DE: 1243 Space geodetic surveys
DE: 1247 Terrestrial reference systems
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting