Statistical evaluation of the passive structure for the vessel detection is considered. The passive detection structure is based on the statistical likelihood ratio test and on the Neyman-Pearson statistical criterion. The assumption is that a vessel is approximately so-called noisy vessel. It means that the underwater acoustic vessel noise is approximately a stationary ergodic stochastic zero ...

Underwater acoustic sensor networks (UASNs) consist of movable and stationary nodes, which usually communicate using the acoustic channel. Underwater acoustic communication networks are particularly susceptible to malicious attacks due to the high transmission power requirements, rapidly changing channel characteristics, multi-path echoes, high bit error rates, high ambient noise, high and vary...

In this work, estimation of high frequency underwater ambient noise spectrum carried out using neural network is reported. The periodic ambient noise data were measured at 5 m depth in Bay of Bengal using omni directional hydrophone. The data were acquired using portable, broadband high frequency data acquisition system. The noise level at high frequencies in the range of 5 kHz to 12 kHz was an...

The purpose of this paper is to compare the efficacy of two algorithms used for denoising underwater acoustic signals affected by ambient noise. The two denoising techniques are, (i) Fourier Bessel (FB) expansion based denoising algorithm and (ii) Empirical Mode Decomposition (EMD)-Fourier Bessel (FB) based denoising algorithm. Sea water normally contains unwanted background noise called ambien...

Marine Engineering faces certain challenges in recent times due to the prevalence of ambient conditions caused by imbalance in the ecosystem. Underwater ambient noise is primarily a background noise, which is a function of time, location and depth. It is of prime importance to detect the signals such as the sound of a submarine or an echo from a target, surpassing and surmounting this ambient n...

Underwater wireless networks consist of mobile and static nodes, which usually communicate using the acoustic channel since radio transmissions attenuate rapidly and optical communication is only suitable for short distances. The underwater acoustic channel is plagued with issues of high transmission power requirements, rapidly changing channel characteristics, multi-path echoes, possible high ...

-The paper introduces LinkQuest Inc.'s cutting-edge high speed underwater acoustic modems. LinkQuest Inc. combined recent advances in high speed digital communication with broadband underwater acoustics in the development of the high speed modems. Advanced Broadband Spread Spectrum Technology results in dramatically increased data rate and robustness and decrease in power consumption. The modem...