(a) Numerically calculated values for , representing the integrated nonlinear loss over the sound beam and thus the nonlinear loss in the s_v measurement. The parameters in Table 1 were used for the calculations. (b) Numerical and experimental values for the ratio between volume backscattering measurements using the “high” and “low” power settings. The experimental data are divided in depth bins with 20 m width, indicating mean values and standard deviations for the 11-hour measurement series.