Laboratory estimation of the bistatic target strength of an axisymmetric elongated body in an acoustic tank

This study addresses the need for experimental validation of the formation mechanisms of bistatic target strength in axisymmetric objects. A laboratory experiment investigating the secondary hydroacoustic field of an axisymmetric elongated body in a bistatic configuration was conducted in the hydroacoustic tank of the St. Petersburg Branch of the Shirshov Institute of Oceanology, Russian Academy of Sciences.

The aim of the experiment was to estimate the bistatic target strength of the axisymmetric elongated body at various body rotation angles and different bistatic angles of the receiving measurement hydrophone. A dedicated experimental methodology was developed, and the necessary equipment for signal acquisition and processing was prepared. The amplitude characteristics and duration of the model echo signal were measured at frequencies of 50–70 kHz for bistatic angles ranging from 10° to 70° and body rotation angles from 0° to 180°. The dependence of bistatic target strength on the bistatic angle and the rotation angle of the axisymmetric elongated body was analyzed. Relationships between the bistatic angle, the body rotation angle, and the characteristics of the echo signal were established.

The obtained results make it possible to refine near-field models of bistatic target strength formation and to assess the influence of geometric and spatial factors on the characteristics of the scattered acoustic field. The experimental relationships can be used to optimize the configuration of transmitting and receiving elements in multistatic underwater surveillance systems. The results provide a comprehensive assessment of the spatiotemporal characteristics of echo signals from axisymmetric objects and may be used to improve underwater surveillance technologies.

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