This is an example of two-point ray tracing in the smoothed Salt Model. Velocity model is specified in file 'sal-mod2.dat'. The model is the version with the most important interfaces: the ocean bottom, the interfaces limiting the salt body, the geopressure horizon and the bottom flat interface. Generation of the selected and other smooth versions of SEG/EAGE Salt Model is described in Building the Salt Model by inversion. Model 'sal-mod2.dat' is an output of history file 'sal-inv2.h'. The name of the model output file was changed from 'sal-m2.out' to 'sal-mod2.dat'.
Computation is performed for one shot in the depth of 20m (file 'sal-src1.dat') at the centre of the square of 21x21 receivers located in the depth of 0m (file 'sal-rec1.dat'). The receiver grid step is 320m. The position of the shot above the salt crest is similar to the original Phase A Acquisition SEG/EAGE where this point is the intersection of two 3-D shot lines (Aminzadeh et al. 1997). Two-point rays of one refracted and three reflected P-waves are computed. Input data for the complete ray tracing are in file 'sal-dcr1.dat', input data specifying the take-off parameters of the required rays are in file 'sal-rp1.dat'. The codes of elementary waves are defined in 'sal-cod1.dat' file. One profile, selected of the 21 x 21 square grid of receivers (file 'sal-rec1.plt'), is used for generation of the ray-theory seismograms in the frequency domain. Computed rays, receivers and source are added into VRML ('sal-ray1.wrl') or GOCAD ('sal-ray1.mx') file with the most important interfaces of the smoothed Salt Model. For more information about this computation see Bucha (2003).
Aminzadeh, F., Brac, J., Kunz, T.: 3-D Salt and Overthrust Models. SEG/EAGE 3-D Modeling Series No.1., Soc. Explor. Geophysicists, Tulsa, 1997.
Bucha, V.: Ray tracing computations in the smoothed Salt Model. In: Seismic Waves in Complex 3-D Structures, Report 13, pp. 241-248, Dep. Geophys., Charles Univ., Prague, 2003.