function obtained for Case II-A and Case II-B, respectively. The overall feature of the mesoscale eddies is well reconstructed. The correlation coefficient ρ is estimated 0.887 and 0.914 for Cases II-A and II-B, respectively. The result of inversion for Case II-C is shown in Fig. 4(c) with the contour plot of the stream function. The model eddy field is poorly reconstructed for this Case. The correlation coefficient with the model eddy field is estimated 0.677 which is very low value in comparison with Case II-B in spite of using the same value of α.
The eddy field reconstructed for Cases I and III by using the optimum value of adetermined 0.3 and 0.75, is shown in Figs. 5(a) and 5(b), respectively. The correlation coefficient ρ is estimated 0.784 and 0.916 for Cases I and III.
We apply this method for the real coastal ocean, where a plan for velocity tomography experiment is made. Figure 6(a) shows the stream function result of ocean model andfive acoustic tomography stations. Because of the very strong tidal flow in the center of the experiment area two tidal vortexes are made. Figure 6(b) shows the inversion result using the travel time differences. Two tidal vortexes are well reconstructed.
5. Conclusion
The computer simulations for the velocity tomography show that the velocity fields of the two-dimensional mesoscale ocean can be reconstructed by using the damped least squares method as the inversion without a priori information, which is difficult to be acquired. The application of this method for the real coastal ocean region also shows good estimation result.
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