Shipping Noise Analysis in Shallow Water and Estimation of Bottom Parameters Using Two Synchronized Vertical Arrays
* Presenting author
Abstract:
Acoustic data were collected in central part of the Sea of Galilee (Lake Kinneret, Israel) in May 2019. As receiving system two synchronized vertical line arrays (VLA) were used. VLAs contained 10 hydrophones each and covered water entire column with depth ~ 40 m, and were deployed at the distance 40 m to each other. Shipping noise was radiated by Research Vessel “Hermona”, moving at the speed ~ 4m/s from VLAs along the straight line connecting arrays up to distance ~ 3 km. Spectrum of the shipping noise was mainly concentrated in low frequency domain (30 – 350 Hz) containing set of discrete peaks. Signal obtained during motion along 1 km was processed and analyzed. Mode filtration was carried out using both VLAs. It was shown that optimal frequency range for correlation analysis and comparison of signals from both VLAs is close to cut-off frequencies for each propagating modes. Addition of phase compensation allows us to extract attenuation coefficients (and other parameters) for mode numbers even bigger than number of elements in VLA. It was shown that usage of two arrays has essential advantages for noise analysis. Comparison of bottom parameters obtained, with data of earlier experiments gives good agreement.