Following upon the catastrophic tsunami of 2004 in southeastern Asia, the prediction of such natural hazards has become an urgent issue. For this purpose, an attractive option is the study of the ocean from space based on the means and methods of remote sensing, which are widely used at present for monitoring processes at the ocean surface and in the atmosphere. The obtained information is characterized by its global scale, high efficiency, and relatively low cost. One of the possible methods for the diagnosis of tsunami waves can be based on the application of radio altimeters, which have already recorded a number of tsunami events in the open ocean, including the tsunami that occurred on December 26, 2004. In the latter case, the anomaly of the ocean surface elevation was equal to ±0.6 m with a characteristic scale of the order of 500 km. Regardless of a high accuracy of determination of the ocean surface displacement (a few centimeters), the information obtained from altimeters is limited by the possibility of obtaining data only along the satellite trajectory. An alternative method for the diagnosis of tsunami waves could consist in observations of the ocean using satellite radars with a synthesized aperture (RSA), in which panoramic images of the sea surface are formed by means of variations in the intensity of small-scale (centimeter-range) wind waves (ripples). If tsunami waves are reflected on RSA images of the ocean surface, the RSA data would not only confirm results of altimetric observations, but also provide important additional information about the geometry of the tsunami wave front. However, the surface manifestations of tsunamis have not been recorded thus far on satellite radar images in the open ocean.
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