Scientific Quarterly Journal of Geosciences

Scientific Quarterly Journal of Geosciences

Improving the Threshold of Detectable Co-Seismic Displacements by Using High Rate GPS Measurements

Document Type : Original Research Paper

Authors
Yahya Djamour 1
S. Tabibi 2
M. M. Hossainali 3
1 Associate Professor, Geomatics College, National Cartographic Center, Tehran, Iran
2 M.Sc. Student, Department of Geodesy, Faculty of Geodesy and Geomatics Engineering, K.N. Toosi University of Technology, Tehran, Iran
3 Assistant Professor,Department of Geodesy, Faculty of Geodesy and Geomatics Engineering, K.N. Toosi University of Technology, Tehran, Iran
10.22071/gsj.2012.54021
Abstract
The accuracy of GPS derived positions in short term measurements largely depends on the better modeling of residual errors which is normally reduced in long term measurements by averaging the obtained results. To increase the accuracy of the movements obtained through the analysis of high rate data in geophysics applications, systematic errors in the existing measurements in the corresponding frequency range should be reduced. Calibration techniques and the error reduction are based on the repeatability of the system constellation. For example, those errors affecting the resulting accuracy of the high rate positions in the time scales of 10-600s depend much on the constellation geometry of the GPS satellites and GPS stations. Since the satellite orbits are fixed, those errors are highly repeatable in time. This characteristic is the base for the development of sidereal filtering techniques for reducing this kind of errors. It is assumed that the repeatability occurs based on the nominal repetition period of the satellites; however, the true time of this repeatability varies even for each satellite. In this paper the mean period is estimated as 23h, 55m, and 55s and used for the noise reduction of time series of the relative displacement. By using this period, noises with frequencies less than 0.01Hz of high rate GPS positions have been reduced significantly. Accessible co-seismic displacements are reduced to less than 4mm in horizontal components and less than 10mm in the vertical components.
Keywords
High-Rate GPS
Relative Displacement
Orbital Repeat Period
Sidereal Filtering
References
Agnew, D. C. & Larson, K. M., 2006- Finding the repeat times of the GPS constellation, GPS Solutions, 10 (4), doi:10.1007/s10291-006-0038-4.
Bock, Y., Prawirodirdjo, L. & Melbourne, T. I., 2004- Detection of arbitrarily large dynamic ground motions with a dense high-rate GPS network. Geophys Res Lett. 31:L06604. doi:10.1029/2003GL019150.
Chen, G., 1998- GPS kinematic positioning for the airborne laser altimetry at Long Valley, Ph.D. dissertation,  Department of Earth Atmospheric and Planetary Sciences, Massachusetts Institute of Technology.
Choi, K., Bilich, A., Larson, K. M. & Axelrad, P., 2004- Modifed Sidereal Filtering: Implications for high-rate GPS positioning, Geophysical Research Letters, 31, L22608, doi:10.1029/2004GL021621.
Elosegui, P., Davis, J. L., Jaldehag, R. T. K., Johansson, J. M., Niell, A. E. & Shapiro, I.I., 1995- Geodesy using the Global Positioning System: the effects of signal scattering on estimates of site position, J. Geophys. Res., 100, 9921–9934.
Genrich, J. F. & Bock, Y., 1992- Rapid resolution of crustal motion at short ranges with the Global Positioning System, Journal of Geophysical Research, 97, 3261-3269.
Herring, T. A., 2010- TRACK GPS kinematic positioning program, version 1.21,Department of Earth Atmospheric and Planetary Sciences, Massachusetts Institute of Technology.  
Herring, T. A., King, R. W. & McClusky, S. C., 2009- GAMIT Reference Manual, Department of Earth Atmospheric and Planetary Sciences, Massachusetts Institute of Technology.
IGS, 2004, 2001, 2002- Annual Report. Pasadena, Jet Propulsion Laborarory.
Ji, C., Larson, K. M., Tan, Y., Hudnut, K. W. & Choi, K., 2004- Slip history of the 2003 San Simeon earthquake constrained by combining 1-hz GPS, strong motion, and tele-seismic data, Geophysical Research Letters, 31, L17608, doi:10.1029/2004GL020448.
Nikolaidis, R. M., Bock, Y., de Jonge, P. J., Shearer, P., Agnew, D. C. & Van Domselaar, M., 2001- Seismic wave observations with the Global Positioning System, Journal of Geophysical Research, 106 , 21,897-21,916.
Park, K. D., Nerem, R. S., Schenewerk, M. S. & Davis, J. L., 2004- Site-specific multipath characteristics of global IGS and CORS GPS sites, J. Geod., 77, 799–803.
Seeber, G., 2003- Satellite geodesy : foundations methods and applications, Berlin, New York, Walter de Gruyter, ISBN: 3110175495, Pages 589.
Seeber, G., Menge, F., Volksen, C., Wubbena, G. & Schmitz, M., 1997- "Precise GPS positioning improvements by reducing antenna and site dependent effects", paper presented at IAG Symposium No. 115, Int. Assoc. of Geod., Rio de Janeiro, Brazil.            
Wubbena, G., Menge, F., Schmitz, M. Seeber, G. & Volksen, C., 1996- A New Approach for Field Calibration of Absolute Antenna Phase Center Variations, Proceedings of ION GPS-96, 9th International Technical Meeting, September 10-17, Kansas City, Missouri, USA.
Scientific Quarterly Journal of Geosciences
Volume 22, Issue 85
Autumn 2013
Pages 55-62