Geodetic Measurement Of Tectonic Deformation In Central California PDF Download

The object of this thesis is to measure directly the tectonic deformation in the Santa Maria Fold and Thrust Belt (SMFTB), northwest of Santa Barbara California. The principal measurement technique is space geodesy, using the signals transmitted by the satellites of the Global Positioning System (GPS). Beyond the introduction, the thesis contains three separate sections, concerning an improved model for drifting oscillators in the satellite and receiver, the analysis of historical surveying measurements, and finally an analysis of 5 years of GPS observations. From March to August 1990, the microwave signals transmitted by the Block II satellites of the Global Positioning System (GPS) were dithered under a policy of "Selective Availability". The dithering appears as a 10 to the minus 9th power deviation of the satellite oscillator frequency, which, when accumulated over several minutes, can produce an error of 100 cycles (20 m) in the model for carrier beat phase. Difference between simultaneously sampling receivers minimizes the error. If, however, the receivers do not sample simultaneously, it is necessary to model the frequency deviation, which we estimate from the phase observed at a station with a stable local oscillator. We apply such a model to data collected in March 1990 by TI4100 and MiniMac receivers sampling at times separated by 0.92 s. Applying the algorithm significantly improves the root mean square (RMS) scatter of the estimated relative position vectors. The RMS scatter from a data set including dithered satellites is similar for both simultaneously and non-simultaneously sampling receivers, a result which indicates that SA can be adequately modeled. We have analyzed geodetic observations to resolve tectonic deformation across the SMFTB. The geodetic network forms a braced quadrilateral with 40 km sides whose southwest corner is the Vandenberg very long baseline interferometry (VLBI) station.