The scientific objective of this research is to understand acoustic wave propagation in a dynamic environment in two frequency bands: Low (50 Hz to 500 Hz) and Mid-to-High (500 Hz to 25 kHz). The goal for the low frequency band is to assess the effects of internal waves on acoustic wave propagation, with an emphasis on the mechanisms that cause significant acoustic temporal and spatial intensit...

The scientific objective of this research is to understand acoustic wave propagation in a dynamic environment in two frequency bands: Low (50 Hz to 500 Hz) and Mid-to-High (500 Hz to 50 kHz). The goal for the low frequency band is to assess the effects of internal waves on acoustic wave propagation, with an emphasis on the mechanisms that cause significant temporal and spatial acoustic fluctuat...

The scientific objective of this research is to understand acoustic wave propagation in a dynamic environment in two frequency bands: Low (50 Hz to 500 Hz) and Mid-to-High (500 Hz to 50 kHz). The goal for the low frequency band is to assess the effects of internal waves on acoustic wave propagation, with an emphasis on the mechanisms that cause significant temporal and spatial acoustic intensit...

The scientific objective of this research is to understand acoustic wave propagation in a dynamic environment in two frequency bands: Low (50 Hz to 500 Hz) and Mid-to-High (500 Hz to 50 kHz). The goal for the low frequency band is to assess the effects of internal waves on acoustic wave propagation, with an emphasis on the mechanisms that cause significant temporal and spatial acoustic intensit...

In the last lecture we saw that the likelihood ratio statistic was optimal for testing between two simple hypotheses. The test simply compares the likelihood ratio to a threshold. The “optimal” threshold is a function of the prior probabilities and the costs assigned to different errors. The choice of costs is subjective and depends on the nature of the problem, but the prior probabilities must...

The influence of intrinsic absorption in a relaxing medium and the resulting three-dimensional diffraction correction of the magnitude of the acoustic pressure averaged over the surface of a receiver is investigated for a tone burst. A rigorous formula for the damped acoustic pressure average at the receiver was obtained for arbitrary pulsed waves in a mono-relaxing medium. Depending on the pul...

This paper is based on analysis of a common source - common gate low noise transconductance amplifier (CS-CG LNTA). Conventional noise analyses equations are modified by considering to the low output impedance of the sub-micron transistors and also, parasitic gate-source capacitance. The calculated equations are more accurate than calculated equations in other works. Also, analyses show that th...

In an environment such as underwater channel where placing test equipments are difficult to handle, it is much practical to have hardware simulators to examine suitably designed transceivers (transmitter/receiver). The simulators of this kind will then allow researchers to observe their intentions and carry out repetitive tests to find suitable digital coding/decoding algorithms. In this p...

The method of Acoustic Wavefield Imaging (AWI) offers many advantages over conventional ultrasonic techniques for nondestructive evaluation, and also provides a means of incorporating fixed ultrasonic sensors used for structural health monitoring into subsequent inspections. AWI utilizes these fixed sensors as wave sources and an externally scanned ultrasonic transducer (or laser interferometer...