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OASR - Examples


  
Figure: 4

>>figs/Kan_fig4.ps,height=7.0cm figure=figs/sand_R.ps,height=6.5cm  

As an example of the use of OASR for computing seismo-acousticreflection coefficients, the following datafile reproduces the results presented for a sand bottom in Stoll and Kan's paper [22]:

Sand. Stoll and Kan 81.
N C Z
2
0 1414 0 0 0 1 0
0 -1800 -600 0.1 0.2 2.0 0
1. 2.E9 .001 2.65 3.6E10 .47 1.E-10 3.9E-5 2.61E7 4.36E7 1.3 1.3 1.25
10 100000 17 4
0 90 181 0
90 0 10 10
0 15 12 5
0 90 12 15
10 100000 1 1
1 20 0.5
0 2000 12 500
-10 10 12 5

Assembled in one plot, Fig.1, the resulting reflection coeffiecients at the 5 frequencies 0.01, 0.1, 1, 10, and 100 kHz reproduce exactly the results shown in Fig. 4 of Stoll and Kan's paper. In addition, the datafile produces the contour plot in Fig.1 of reflection coefficients vs angle and frequency.


  
Figure: Reflection coefficients vs frequency and angle for (a) a 1 meter layer of porous sand overlying a ``soft'' halfspace, and (b) a 1 meter thick ``soft'' layer overlying a sand halfspace. Prameters for both media are consistent with those given by Stoll and Kan.

OASES handles arbitrary poro-elastic stratifications, and Fig.2(a) shows the equivalent frequency-angle contours of the reflection coefficient of a 1 m thick layer of sand overlying Stoll and Kan's ``soft'' sediment. Similarly Fig.2b) shows the reflection coefficients for a 1 meter ``soft'' layer over sand. The datafile for generating Fig.2(a) is

1 m Sand over Soft.
N C Z
3
0 1414 0 0 0 1 0
0 -1800 -600 0.1 0.2 2.0 0
1. 2.E9 .001 2.65 3.6E10 .47 1.E-10 3.9E-5 2.61E7 4.36E7 1.3 1.3 1.25
1.0  -1800 -600 0.1 0.2 2.0 0
1. 2.E9 .001 2.65 3.6E10 .76 1.6E-15 1.56E-7 2.21E7 3.69E7 4.3 4.3 1.25
10 100000 17 4
0 90 181 0
90 0 10 10
0 15 12 5
0 90 12 15
10 100000 1 1
1 10 0.5
0 2000 12 500
-10 10 12 5


next up previous contents
Next: OAST: OASES Transmission Loss Up: OASR: OASES Reflection Coefficient Previous: Output Files
henrik schmidt
1999-08-25