Time derivatives of the spectrum: Relaxing the stationarity assumption

Details Time derivatives of the spectrum: Relaxing the stationarity assumption Time derivatives of the spectrum: Relaxing the stationarity assumption

Dec 2005

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005agufm.s31c..06p&link_type=abstract

American Geophysical Union, Fall Meeting 2005, abstract #S31C-06

Statistics

Computation

0910 Data Processing, 3255 Spectral Analysis (3205, 3280), 3270 Time Series Analysis (1872, 4277, 4475), 5200 Planetary Sciences: Astrobiology, 7290 Computational Seismology

Scientific paper

Spectrum analysis of seismic waveforms has played a significant role towards the understanding of multiple aspects of Earth structure and earthquake source physics. In recent years the multitaper spectrum estimation approach (Thomson, 1982) has been applied to geophysical problems providing not only reliable estimates of the spectrum, but also estimates of spectral uncertainties (Thomson and Chave, 1991). However, these improved spectral estimates were developed under the assumption of local stationarity and provide an incomplete description of the observed process. It is obvious that due to the intrinsic attenuation of the Earth, the amplitudes, and thus the frequency contents are changing with time as waves pass through a seismic station. There have been incredible improvements in different techniques to analyze non-stationary signals, including wavelet decomposition, Wigner-Ville spectrum and the dual-frequency spectrum. We apply one of the recently developed techniques, the Quadratic Inverse Theory (Thomson, 1990, 1994), combined with the multitaper technique to look at the time derivatives of the spectrum. If the spectrum is reasonably white in a certain bandwidth, using QI theory, we can estimate the derivatives of the spectrum at each frequency. We test synthetic signals to corroborate the approach and apply it the records of small earthquakes at local distances. This is a first approach to try and combine the classical spectrum analysis without the assumption of stationarity that is generally taken.

Affiliated with

Also associated with

No associations

Rating

Time derivatives of the spectrum: Relaxing the stationarity assumption does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Time derivatives of the spectrum: Relaxing the stationarity assumption, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Time derivatives of the spectrum: Relaxing the stationarity assumption will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-751321