Underwater communication in sea environment is very challenging due to extended multipath propagation, dispersion and fading effects. Communication system, in which noise-like signals are used as an information carrier are investigated in this study. The process of cross correlation at the receiver is used for detection of transmitted information. This feature achieves Low Probability of Detect...

In this paper, intelligent guidance and control laws are developed for an autonomous underwater vehicle to engage underwater targets. The engagement of underwater targets is suffered from uncertainties of the complicated underwater environment, short detecting range of the sonar seeker, the low speed ratio between vehicle and target, and longtime operations but no accurate positioning technique...

Based on a fluid-structure interaction analysis (FSIA), the theoretical solution is developed for an integrated spherical shell-damping layer-water interaction system subjected to an internal sinusoidal pressure excitation. The effect of damping layer on reducing underwater noises is investigated. The pressure reduction factor is defined to measure the efficiency of noise reduction by the dampi...

Laser sensing has been applied in various underwater applications, ranging from underwater detection to laser underwater communications. However, there are several great challenges when profiling underwater turbulence effects. Underwater detection is greatly affected by the turbulence effect, where the acquired image suffers excessive noise, blurring, and deformation. In this paper, we propose ...

Nearly 70% of our planet is composed of an aquatic environment, however, due to the lack of appropriate scientific tools and also the relative hostility of the acquatic environment, much of it still remains unexplored. With the advent of global climatic changes, a pronounced energy crisis and changing ecological habitats understanding the oceans of our planet is of vital importance. Monitoring ...

For the underwater degenerative image caused by obscure and noise, atmospheric turbulence model is utilized to construct the restoration model. By computing the underwater image quality function which is used to estimate the adaptive degradation model parameter, underwater image is restored through Wiener filters. The connection between image contrast and average gradients and model parameter i...

The impact of the noise radiated from merchant ships on marine life has become an active area research. In this paper, a methodology integrating observation at single location and modelling whole field in shallow waters is presented. Specifically, underwater data opportunistic Zhoushan Archipelago were collected least one day each month January 2015 to November 2016. analyzed modified empirical...

Passive acoustics has been identified as an important strategy to determine underwater gas flux at natural sites, or locations related anthropogenic activities. The ability of acoustic system detect, quantify and locate a leak is fundamentally controlled by the Signal Noise Ratio (SNR) bubble sounds relative ambient noise. This work considers use beamforming methods enhance SNR so improve perfo...

The amount of underwater sound from ship traffic, commercial, research, and military sound sources has increased significantly over the past century. Marine mammals and many other marine animals rely on sound for shortand long-range communication, for orientation, and for locating prey. This reliance has raised concern that elevated sound levels from human sources may interfere with the behavio...