Images of the Seabed of the Gulf of Gdańsk Obtained by Means of the Parametric Sonar

The main goal of this paper is to present results of the experimental investigation of the seabed by means of parametric echosounder in the form of chosen images. The phenomena of nonlinear interaction between two parallel beams of high intensity gives as a results very narrow beam of low frequency wave, that enables to penetrate the sea bottom. The first step of our investigations was calibration of all the elements of the measuring system. In the second step the marine trials were carried out. For this purpose the mobile measuring set up was installed on the board of sailing boat. The details about the measuring devices can be found below. The main goal of these investigations was to determine the structure of the seabed for different places of the Gulf of Gdańsk. The special features of parametric generation of sound beam allow to penetrate the bottom for more then several meters. At the end of the paper, a set of images that illustrated the results of investigations has been presented.