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One Year of Daily Satellite Orbit and Polar Motion Estimation for Near Real Time Crustal Deformation Monitoring, Proceedings IAU Symposium No. 156

Yehuda Bock, Jie Zhang, Joachim F. Genrich, Peng Fang, & Keith F. Stark

Published September 1992, SCEC Contribution #33

The Permanent GPS Geodetic Array (PGGA) in southern California consists of five continuously operating stations established to monitor crustal deformation in near real time. The near real time requirement has been problematic since GPS satellite ephemerides and predicted earth orientation values (IERS Bulletins A and B) have been found to be neither sufficiently timely nor accurate to achieve horizontal position accuracies of several mm on regional scales. Therefore, we have been estimating precise GPS ephemerides and polar motion since August 1991. An examination of overlapping 24-hour values of pole position. These products are sufficiently timely and accurate to achieve several mm long-term horizontal precision in regional scale measurements of crustal deformation in near real time, as has been demonstrated during the 28 June, 1992 Landers and Big Bear earthquakes in southern California. The PGGA stations were able to detect seismically induced, sub=centimeter-level motions with respect to a terrestrial reference frame defined by the global tracking stations.

Citation
Bock, Y., Zhang, J., Genrich, J. F., Fang, P., & Stark, K. F. (1992, 9). One Year of Daily Satellite Orbit and Polar Motion Estimation for Near Real Time Crustal Deformation Monitoring, Proceedings IAU Symposium No. 156. Poster Presentation at International Astronomical Union Symposium.