It has always been difficult to achieve accurate information of the channel for underwater acoustic communications because severe propagation conditions, including frequency-selective property, high relative mobility, long latency, and intensive ambient noise, etc. To this end, a deep unfolding neural network based approach is proposed, in which multiple layers mimic iterations classical iterat...

6 [1] Interstation cross correlations of ambient seismic noise from 1 year of continuous data at periods 7 between 6 and 50 s are used to study the origin of the ambient noise using stations located in Europe, 8 southern Africa, Asia, and three regions within North America. The signal-to-noise ratios (SNR) of 9 Rayleigh waves for positive and negative correlation time lags at periods of 8, 14, ...

As the main way of underwater wireless communication, underwater acoustic communication is one of the focuses of ocean research. Compared with the free space wireless communication channel, the underwater acoustic channel suffers from more severe multipath effect, the less available bandwidth and the even complex noise. The underwater acoustic channel is one of the most complicated wireless com...

In this paper, we propose an underwater object detection method using monocular vision sensors. In addition to commonly used visual features such as color and intensity, we investigate the potential of underwater object detection using light transmission information. The global contrast of various features is used to initially identify the region of interest (ROI), which is then filtered by the...

This paper handles the issue of identifying the whistle of a dolphin in the presence of noise. When a recorded underwater signal containing other sounds is given to a system, it detects and identifies the presence of dolphin whistle. Analyzing the extracted underwater sounds gives meaningful information about the environment. Also, the presence of a particular underwater species and their behav...

In this paper, we propose a new stereo measurement method of objects in liquid whose refractive index is unknown. In recent years, demands for underwater tasks, such as digging of ocean bottom resources, exploration of aquatic environments, rescues, and salvages, have increased. Therefore, underwater robots or underwater sensing systems that work instead of human become important, and technolog...

[1] Based on year-long cross-correlations of broad-band seismic records obtained at sixty-six stations within or adjacent to the Pacific Basin, we show that broad-band ambient noise is observed to propagate coherently between island stations and between island and continent stations. For many station pairs, high signal-to-noise ratio (SNR) fundamental mode Rayleigh wave Green functions are obse...

In this study, we cross-correlate waveforms of ambient seismic noise between 6 and 100 sec to study the origin of ambient seismic noise. We use one year of data recorded at numerical stations located in Europe, North America, and southern Africa. We measure the signal-to-noise ratios (SNR) of Rayleigh waves for positive and negative correlation time lags at periods of 8, 14, 25 and 50 sec to de...