Methods of sonar signal processing to solve the sensing bottom surface problem

The paper deals with the processing of hydroacoustic data recorded with help of hydroacoustic research complexes. Particular attention to classic and interferometric sonars is paid. In accordance to the regulatory documentation, the minimum permissible measurement errors for the formation of bottom surface maps for various economic sectors are determined.
As one of the important problems affecting the effectiveness of survey work with sonar complexes, the authors determine the problem of primary data compression, which, as a rule, leads to information loss without the possibility of its recovery. These drawbacks of the methods of primary information compression-recovery and processing of hydroacoustic data used in complexes reduce the overall effectiveness of the complexes usage both with the use of sidescan sonar and with the use of an interferometric side-scan sonar.
In the framework of a numerical experiment, it has been shown that the use of chirp signals as probing pulses makes it possible to effectively apply the complex in the survey sonar mode.
The results of the numerical experiment for estimating the spatial position of the object at the bottom of the sonar images using the phase difference information of the received signals using an interferometric sonar are presented. Based on the results of the experiment, the requirements for recording quality of reflected signals of various types in interferometric side-scan sonar are determined.
A method of resolving the reflected (with partial overlap and overlay) hydroacoustic tones, based on the method of dividing the spectra is proposed by the authors. To improve the efficiency of the chirp signal processing, the authors suggest to improve the accuracy of the detection of the signal detection time due to the phase correction calculated through the slope of the frequency change rate of the chirp signal.