Capacity analysis of underwater visible light communication systems over a lossy channel in the presence of noises.

Absorption and scattering losses due to impurities and turbidity in the water affect the transmission quality of underwater visible light communication links, restricting the channel capacity. For the first time to our knowledge, this paper analytically studies the channel capacity of a point-to-point underwater visible light communication link in the presence of input-independent and -dependent noises along with absorption and scattering losses. This way, novel lower and upper bound expressions on channel capacity are derived when average and peak-intensity constraints are imposed on the channel input.

Left-Right ambiguity resolution for coprime sparse arrays.

Coprime Sparse Arrays (CSA) with two collocated uniform linear arrays are used to estimate O(MN) direction of arrivals for a narrow band source with only O(M+N) sensors. The CSA cannot discriminate the azimuth and its complementary angles due to the symmetry along the array-axis. The bearing ambiguity, also referred to as a Left-Right (LR) ambiguity, is addressed in this paper using CSA.

Steerable sparse linear array design based on compressive sensing with multiple measurement vectors.

This paper presents the synthesis of a non-uniform linear array for two-dimensional Range-Bearing underwater acoustic imaging based on the multiple beam, measurement vectors (MMV) Compressive Sensing (CS) method. This method considers multiple steering directions in the mathematical model and exploits the sparsity of the oversampled linear aperture to obtain a thinned array structure. In this paper, a simulation study to synthesise the sparse linear array (SLA) for a Forward Looking Sonar system considering multiple beams in the field of view (FOV) was conducted.

Design and analysis of air acoustic vector-sensor configurations for two-dimensional geometry.

Acoustic vector-sensors (AVS) have been designed using the P-P method for different microphone configurations. These configurations have been used to project the acoustic intensity on the orthogonal axes through which the direction of arrival (DoA) of a sound source has been estimated. The analytical expressions for the DoA for different microphone configurations have been derived for two-dimensional geometry.

A multimodal detection model of dolphins to estimate abundance validated by field experiments.

Abundance estimation of marine mammals requires matching of detection of an animal or a group of animal by two independent means. A multimodal detection model using visual and acoustic cues (surfacing and phonation) that enables abundance estimation of dolphins is proposed. The method does not require a specific time window to match the cues of both means for applying mark-recapture method.

Radiated signal characteristics of marine vessels in the cepstral domain for shallow underwater channel.

This work examines the distribution of cepstral energy of the radiated signal of a marine vessel and the underwater channel modeled as a block-adaptive linear system. Detailed simulation analysis of the signal at the receiver of a passive sonar has led to the observation that, in the cepstral domain the radiated signal of a marine vessel largely occupies the lower cepstral indices while the underwater channel occupies the higher indices, such that for several range and depth conditions, the two can be separated out. This finding can facilitate the design of filters in the cepstral domain for reducing distortions due to the underwater channel.

Localization of sperm whales in a group using clicks received at two separated short baseline arrays.

In this paper, a sperm whale click analysis scheme is proposed in order to calculate the position of individual sperm whales in a group using data received at two arrays deployed near the surface. The proposed method mainly consists of two parts: short baseline (SBL) with classification and long baseline (LBL) with class matching. In SBL with classification, a click is automatically detected, and its direction of arrival is calculated.