In order to estimate the sound intensity level of vertical transmit array(VTA)from that of single transducer,a fast estimation method of transmit array gain(TAG)in Pekeris waveguide is studied.At first,the average sou...In order to estimate the sound intensity level of vertical transmit array(VTA)from that of single transducer,a fast estimation method of transmit array gain(TAG)in Pekeris waveguide is studied.At first,the average sound intensity of VTA is calculated on the basis of normal mode theory with the effective depth,and the TAG expressed by the summation of modes is derived.Then by using integral,instead of summation,of modes order,the fast estimation expression of TAG in 3/2 power field is derived along with error correction.Because only the first mode exists in effective shadow zone(ESZ),the fast estimation expression of TAG in ESZ is derived by directly simplifying the former expression.All of the fast estimation errors of computer simulations and experiment in shallow water are less than 1 dB,which can verify the validity of the fast estimation method.This fast estimation method of TAG can provide references for practical application.展开更多
Prom investigation of the advantages and disadvantages of conventional tri-voltage method,a method for the measurement of the transmitting transducer＇s impedance was presented to solve the difficult problem of examin...Prom investigation of the advantages and disadvantages of conventional tri-voltage method,a method for the measurement of the transmitting transducer＇s impedance was presented to solve the difficult problem of examining the consistency of the transmitting phased array on the single-mode excitation sea spot.In the method based on the system function, the circuit structure of tri-voltage method was used but new parameters were measured.The principle of the method was given first.Then when resistors with different nominal values were used in the circuit,the measured results for the impedance of transducers were reported.The results were compared with the higher precision impedance analyzer.Finally,the error analysis was performed according to the impedance formula and the equivalent circuit parameters were fitted.Under the condition of guaranteeing the sampling precision,by performance analyzing, the resistor value in series was chosen relatively smaller than the impedance of transducer,the measurement of impedance could achieve the same precision as the higher precision impedance analyzer.Finally,the least squares curve-fitting of measured curves indicated that the transducer equivalent electrical parameters could be extracted accurately and used to design the matching network.展开更多
基金supported by the National Natural Science Foundation of China(Y211071131,11704396)。
文摘In order to estimate the sound intensity level of vertical transmit array(VTA)from that of single transducer,a fast estimation method of transmit array gain(TAG)in Pekeris waveguide is studied.At first,the average sound intensity of VTA is calculated on the basis of normal mode theory with the effective depth,and the TAG expressed by the summation of modes is derived.Then by using integral,instead of summation,of modes order,the fast estimation expression of TAG in 3/2 power field is derived along with error correction.Because only the first mode exists in effective shadow zone(ESZ),the fast estimation expression of TAG in ESZ is derived by directly simplifying the former expression.All of the fast estimation errors of computer simulations and experiment in shallow water are less than 1 dB,which can verify the validity of the fast estimation method.This fast estimation method of TAG can provide references for practical application.
基金supported by the National Natural Science Foundation of China(11004214,10574137)
文摘Prom investigation of the advantages and disadvantages of conventional tri-voltage method,a method for the measurement of the transmitting transducer＇s impedance was presented to solve the difficult problem of examining the consistency of the transmitting phased array on the single-mode excitation sea spot.In the method based on the system function, the circuit structure of tri-voltage method was used but new parameters were measured.The principle of the method was given first.Then when resistors with different nominal values were used in the circuit,the measured results for the impedance of transducers were reported.The results were compared with the higher precision impedance analyzer.Finally,the error analysis was performed according to the impedance formula and the equivalent circuit parameters were fitted.Under the condition of guaranteeing the sampling precision,by performance analyzing, the resistor value in series was chosen relatively smaller than the impedance of transducer,the measurement of impedance could achieve the same precision as the higher precision impedance analyzer.Finally,the least squares curve-fitting of measured curves indicated that the transducer equivalent electrical parameters could be extracted accurately and used to design the matching network.
