Comparison of the results of measurements of the source underwater noise levels obtained by the direct method and using vector-phase processing

Abstract

Object and purpose of research. Moving broadband source underwater noise level estimations obtained by direct and indirect methods using a receiver for the measurement of sound pressure and sound particle velocity components combined. Materials and methods. Theoretical research using computer simulation, full-scale experiments in real measurement conditions, statistical analysis of experimental results. Main results. The noise level estimations obtained by the direct method, only through the sound pressure channel, and by the indirect method with recalculating the values of sound intensity were compared based on representative samples under ideal conditions and in real water area conditions. Conclusion. Under ideal measurement conditions a statistically significant difference between the two estimation methods occurs only at frequencies below 16 Hz. The results of a full-scale experiment in real conditions show that the estimate obtained on the basis of the spatial selective sound intensity vector is characterized by greater reliability and accuracy since it is less affected by reflections from the boundaries of the water area.