| The development of three pressure-velocity (p-u ) probes and two pressure-acceleration (p-a) probes is presented. Four of the probes are designed for operation below 1 kHz and one of the probes is designed for operation below 10 kHz. Because the probes can measure both the potential and kinetic components of the acoustic field, they are suitable for intensity measurements and/or impedance measurements. This was demonstrated through a series of experiments using slow waveguides, open water test facilities, and anechoic tank facilities.;An analysis of slow waveguides is presented as it pertains to the calibration of intensity probes. The results show that while the acoustic environment is dispersive and lossy, fairly accurate calibrations can be performed under the assumption that the waveguide exhibits ideal standing wave behavior.;An experiment was performed to evaluate the use of the intensity technique to filter hydrodynamic flow noise resulting from towing a single component p-a probe though a large body of water. The results suggest that the intensity technique is viable provided that there is a low degree of statistical correlation between the hydrodynamic pressure and velocity fields and the data can be acquired with a sufficiently large number of averages so that cross-spectrum of the noise signal is minimized. |
