It has been necessary to solve the problem of transmitting to the operator the information received by the underwater dosimetric complex within the framework of the studies devoted to estimations of radioactive contamination of the bottom surface of deep-sea areas. The use of a standard radio channel under these conditions has been impossible, and therefore, it is expedient to use an ultrasonic channel of information transmission. Thus, the issue of ultrasonic anisotropic radiation transmission in deep-water sea areas has been considered. Anisotropy of radiation is necessary to reduce the error and increase the reliability of information transmission. A boundary value problem to estimate the ultrasound pressure on the aquatic medium has been formulated and its solution as a wave equation in seawater has been provided. Attention has been paid to such characteristics of seawater areas as water salinity, liquid column pressure determining its density, temperature, and range of radiation propagation with allowance for its frequency characteristics. The problem has been solved by the known method of separation of variables in spherical geometry with allowance for the anisotropy of radiation, the specified characteristics of which are determined on the basis of the optimal selection of the radiation direction to the ultrasonic buffer device located on the water surface of the water area that is determined experimentally. The results of calculations have shown that, at the radiation frequency of 1 kHz, the detector reliably registers the signal at a distance of ~1 km. As the frequency increases, the signal is noticeably absorbed and, at a radiation frequency of ~40 kHz, begins to drop sharply from a distance of ~20 m. Similar results have been obtained when the problem is solved in the form of radiation of a wide beam. The results of solving the problems make it possible to formulate certain requirements for the design of ultrasonic detectors used for underwater transmission of information, which will make it possible to implement the method of information transmission from deep-water areas when using an underwater dosimetric complex and, in addition, to develop a sound method of communication in deep-water areas, which will play a significant role in solving the problems of information transmission under these specific conditions.
Elokhin et al. (Mon,) studied this question.