(a) original signal, (b) downsampled signal, (c) Methyl jasmonate site low-pass filtered signal.10 two 0 –
(a) original signal, (b) downsampled signal, (c) low-pass filtered signal.ten two 0 -2 0U/v-14 of(a)five 10–(b)-4 0 4 2 0 -2 -4 0 5 10 15 20 25 30 10-5 five ten 15 20 25(c)t/sFigure 15. 8103 time domain waveform. (a) original signal, (b) downsampled signal, (c) low-pass 8103 time domain waveform. (a) original signal, (b) downsampled signal, (c) low-pass filtered signal. filteredThrough the cross-correlation processing of the vector hydrophone along with the 8103 stress signal, the correlation coefficients obtained from Figures 12c and 13c are shown J. Mar. Sci. Eng. 2021, 9, x FOR PEER Review 15 of 18 in Figure 16a. The correlation coefficients obtained from Figures 14c and 15c are shown in Figure 16b.Correlation coefficient(a)Correlation coefficient(b)Figure 16. Time-domain signal correlation coefficient. (a) dd m, (b) dd = 3.45 m. Figure 16. Time-domain signal correlation coefficient. (a) dd ==00m, (b) dd = three.45 m.It might be obtained from Figure 16 that when the vector hydrophone and 8103 had been Based Cholesteryl sulfate Purity & Documentation around the above test outcomes, the hydrophone measures the pressure transform deployedthe elasticthe signals obtained sensitive element. Fluid velocity modifications and denthrough collectively, deformation on the are correlated, along with the delay difference is 0. When the vector hydrophone and 8103 had been deployed separately at bands, the stress signal sity adjustments can cause pressure modifications. In pretty low frequency a distance of 3.45 m, the delay difference is 0.5 s. The calculated wave velocity is 6.9 m/s, the velocities of gravity essentially measured by the hydrophone is triggered by fluid velocity modifications, which is hywaves and sound waves can 7 m/s and 1500 m/s, respectively. It proves that the signal drodynamic pressure. It are be assumed that the fluid is definitely an incompressible fluid. Therereceived by the is often measuredgravity vectorrather than a sound wave. fore, the AFSD hydrophone is really a with a wave hydrophone. Primarily based on the above test outcomes,=the hydrophone measures the stress alter by way of The pressure spectrum at z d can be obtained through the time domain signal. the elastic deformation from the sensitive element. Fluid velocity adjustments and density alterations The connection among the amplitude with the stress generated underwater and the can cause pressure changes. In really low frequency bands, the stress signal in fact amplitude in the surface stress is P0 = Pz cosh( kh ) / cosh ( k ( h + d ) ) , the surface pressure measured by the hydrophone is brought on by fluid velocity alterations, which is hydrodynamic spectrum could be obtained via the connection. Take 30 s fluid. Consequently, the AFSD stress. It may be assumed that the fluid is an incompressibletime domain signal and use the Welch periodogram to acquire the power spectrum. Spectral resolution is 0.0333 Hz. Figcan be measured having a vector hydrophone. ure 17 shows environmental at z =spectrum and the surface stress spectrum obtained The stress spectrum noise d could be obtained by way of the time domain signal. by relationship between the motion at in the pressure generated underwater as well as the Thethe target heave and sway amplitude 0.43 Hz. The horizontal axis will be the frequency in the hydrodynamic wave, the left P0 = P cosh(kh)/ size of h + d)), the surface stress amplitude in the surface stress isverticalz axis is definitely the cosh(k(the hydrodynamic pressure spectrum, as well as the proper vertical axis would be the corresponding pressure domain signal The spectrum is usually obtained by means of the partnership. Take 30 s time spectrum leve.
