A two-hydrophone transfer function method for measuring low-frequency acoustic propertics and its error analysis

The complex reflection coefficient of materials can be calculated from the transfer function measurement between two hydrophones in water-filled tube. The character of the transfer function, the reflection coefficient and phase contours were investigated. The measuring error of the transfer function and the calculation error of the complex reflection coefficient were discussed simultaneously. The conclusion is that the measurement results in the required range can be worked out with better precision by choosing the proper two-hydrophone position parameters, raising S/N and correcting the sound speed in water. Therefore, these can be compared with the results obtained by SWR method.