Comparison of techniques that use the single scattering model to compute the quality factorQ from coda waves

1991 ◽  
Vol 135 (1) ◽  
pp. 77-89 ◽  
Author(s):  
David A. Novelo-Casanova ◽  
W. H. K. Lee
Keyword(s):  
Single Scattering ◽  
Coda Waves ◽  
Scattering Model ◽  
Comparison Of Techniques ◽  
Quality Factorq

Laser Doppler measurement of retinal blood velocity: validity of the single scattering model

1985 ◽  
Vol 24 (5) ◽  
pp. 605 ◽  
Author(s):  
Charles E. Riva ◽  
Juan E. Grunwald ◽  
Benno L. Petrig
Keyword(s):  
Single Scattering ◽  
Blood Velocity ◽  
Laser Doppler ◽  
Doppler Measurement ◽  
Scattering Model

Experimental and theoretical low-energy photoelectron diffraction study of the W(001) surface: Adequacy of a single scattering model

1987 ◽  
Vol 185 (3) ◽  
pp. L527-L533 ◽  
Author(s):  
D. Sebilleau ◽  
M.C. Desjonqueres ◽  
D. Chauveau ◽  
C. Guillot ◽  
J. Lecante ◽  
...  
Keyword(s):  
Diffraction Study ◽  
Single Scattering ◽  
Low Energy ◽  
Scattering Model ◽  
Photoelectron Diffraction

A practical analytic single scattering model for real time rendering

2005 ◽  
Vol 24 (3) ◽  
pp. 1040-1049 ◽  
Author(s):  
Bo Sun ◽  
Ravi Ramamoorthi ◽  
Srinivasa G. Narasimhan ◽  
Shree K. Nayar
Keyword(s):  
Real Time ◽  
Single Scattering ◽  
Scattering Model

scholarly journals Attenuation of Coda Waves in the Central Region of the Gulf of California, México

2017 ◽  
Vol 56 (2) ◽  
Author(s):  
Héctor E. Rodríguez-Lozoya ◽  
Tonatiuh Domínguez R. ◽  
Luis Quintanar Robles ◽  
Armando Aguilar Meléndez ◽  
Héctor E. Rodríguez-Leyva ◽  
...  
Keyword(s):  
Central Region ◽  
Gulf Of California ◽  
Single Scattering ◽  
Coda Waves ◽  
Tectonic Activity ◽  
S Wave ◽  
A Value ◽  
Wave Travel ◽  
Coda Attenuation ◽  
North And South

Coda waves were analyzed from events recorded by NARS seismic network deployed along both margins of the Gulf of California, Mexico, to estimate coda attenuation Qc. Sato’s (1977) single scattering model was used for a coda window of 20 to 25 s beginning at twice the S-wave travel time. Events recorded from 2003 to 2007 located in the central region of the Gulf of California were analyzed. Source-to-receiver distances are between 40 and 500 km. Assuming a power law of the form QC (f) = QO f a, QC values were averaged and a value of QO = 83±3 and a frequency-dependence α value of 1.06±0.03 in the frequency range from 1 to 7 Hz was obtained. QO value and the high frequency dependency agree with the values of other regions characterized by a high tectonic activity. Based on source-station distribution two subregions (north and south) were defined. QC values were calculated and correlated with tectonics and morphology of each area. The observed higher attenuation in the south region can be attributed to the fact that south region is more fractured since the greater earthquakes occur in central to south Gulf of California and the oceanic crust is reported to be thinner in the southern region.

Attenuation of coda waves at the Cerro Prieto geothermal field, Baja California, Mexico

1997 ◽  
Vol 87 (5) ◽  
pp. 1368-1374
Author(s):  
Tonatiuh Domínguez ◽  
Cecilio J. Rebollar ◽  
Hubert Fabriol
Keyword(s):  
Baja California ◽  
Hot Springs ◽  
Single Scattering ◽  
Geothermal Field ◽  
Coda Waves ◽  
S Wave ◽  
Low Frequencies ◽  
S Waves ◽  
A Value ◽  
Cerro Prieto

Abstract We analyzed coda waves from 22 local events recorded by a temporary network of seismic stations deployed in the Cerro Prieto geothermal field of Baja California, Mexico, to estimate coda attenuation Qc in the frequency range 6 to 24 Hz. We used Sato's (1977) single scattering model for a coda window of 12.5 ± 2.5 sec beginning at twice the S-wave travel time. All events analyzed were located within the exploitation area with depths up to 6 km and source-to-receiver distances less than 8 km. At frequencies of 3, 4, and 5 Hz, rms amplitudes of coda to S waves showed no clear decay or even negative Qc values. This could be due to the inability of the theory to fit the data at low frequencies as it was suggested by Fehler et al. (1992). Within the range of variation, five of the seven stations showed similar Qc values that ranged from about 200 at 6 Hz to about 490 at 24 Hz. Assuming a power-law dependence of the form Qc (ƒ) = Q0ƒη, we estimated a value of Q0 = 111.5 ± 23 and a frequency dependence η of 0.41 ± 0.1. We found site effects at two stations that were located close to hot springs and mud pools.

Seismic attenuation tomography of the North-Western Himalaya using Coda waves

2020 ◽  
Author(s):  
Amit Bera ◽  
Himanshu Agrawal ◽  
Supriyo Mitra ◽  
Shubham Sharma
Keyword(s):  
Quality Factor ◽  
Western Himalaya ◽  
Coda Waves ◽  
Projection Algorithm ◽  
Lapse Time ◽  
Scattering Model ◽  
The North ◽  
Temporal Decay ◽  
Back Scattering ◽  
Least Squares Approach

<p>We use 4695 local waveforms from 1206 earthquakes (epicentral distance < 350 km and 2.0 ≤ Mw ≤ 5.5) recorded by IISER Kolkata network (IK) at 22 stations (32°N to 35°N latitude and 74°E to 77°E longitude), located within the North-Western Himalaya (28°N to 39°N latitude and 68°E to 81°E longitude). We study the coda waves which are generally the tail of a seismogram and arrive after the main seismic waves. We use the temporal decay of coda amplitude to calculate the coda quality factor (Q<sub>c</sub>) from which we estimate the attenuation (Q<sub>c</sub><sup>-1</sup>). We consider the single back-scattering model (Aki & Chouet, 1975) where both the scattering (Q<sub>sc</sub><sup>-1</sup>) and intrinsic (Q<sub>i</sub><sup>-1</sup>) component of the attenuation are included in the measurement. We use a lapse time of 2t<sub>s</sub> (t<sub>s</sub> is the S-wave arrival time) as the starting point of the coda window. Then, we consider multiple forward-scattering model, where the attenuation (Q<sub>c</sub><sup>-1</sup>) is dominantly dependent on the intrinsic (Q<sub>i</sub><sup>-1</sup>) component. In this model we use lapse time greater than 2t<sub>s</sub> so that the coda waves encounter multiple scatterers and enter the diffusive regime. We calculate the frequency dependent quality factor for each earthquake-receiver path at frequencies 1 to 14 Hz using the linear least squares approach on temporal decay of coda amplitude. We calculate Q<sub>0</sub> (quality factor at a reference frequency f<sub>0</sub> which is chosen to be 1 Hz for the analysis) and its frequency dependence (η) using weighted least squares approach on the power law dependence of Q<sub>c </sub>on frequency. To see the lateral variation of Q in our study area, we have produced 2-D maps by combining the Q<sub>c </sub>measurements together in a tomography. For single back-scattering model we use the back-projection algorithm which is based on the calculation of area overlap of ellipses with the gridded region. For multiple forward-scattering model, the same back-projection algorithm is modified to calculate the length overlap of traces with the gridded region. To understand the spatial resolution of the 2-D Q<sub>c </sub>maps, we use the point spreading function test which quantifies the recovery of Q<sub>c </sub>perturbation. In addition to this, we also perform a standard checkerboard resolution test to ensure simultaneous recovery of Q<sub>c </sub>perturbation. We observe low Q in the Kashmir basin and Lesser Himalaya and high Q in surrounding northeastern Higher Himalaya which clearly correspond to the coda wave attenuation signatures in the older Tethyan sedimentary rocks and crystalline igneous rocks in these regions respectively.</p>

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