Modulated Laser Line Scanner for Enhanced Underwater Imaging

Abstract

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Underwater Optical Imaging: The Past, the Present, and the Prospects

“…In the case of temporally modulated waveforms, the initial work of Mullen et al was geared toward improving the imaging capability of the Raytheon Laser Line Scan System discussed above [77]. Desired outcomes of the advanced system were less sensitive to solar radiation, and a decrease in the near field, backscatter component.…”

An underwater chaotic lidar sensor based on synchronized blue laser diodes

“…[1][2][3][4][5][6] Recent work has demonstrated the advantages of wide bandwidth intensity modulation for operation in turbid waters, where high temporal resolution can allow discrimination between the unwanted backscatter signals and the desired return signals from objects of interest. [7][8][9][10][11] Chaotic lidar is a wide bandwidth approach that has been successfully used for turbid water impulse response and ranging measurements.…”

Image enhancement of underwater target detection by inhomogeneous illumination

“…However, the characteristic of the laser light field is in fact the same as that of general light mentioned above, i.e., evenly distributed intensity at the cross-section of the beam and FOV. To solve the backscattering problem, techniques of synchronous scanning and range-gated have been developed, which can effectively decrease the backscattering and increase the visible distance [4] [8]. But the laser approach is based on depressing single-way scattering.…”