Abstract

Radar modulation, demodulation, and signal processing techniques have been merged with laser imaging to enhance visibility in murky underwater environments. The modulation provides a way to reject multiple scattered light that would otherwise reduce image contrast and resolution. Recent work has focused on the use of wideband modulation schemes and digital passband processing to resolve range details of an underwater scene. Use of the CLEAN algorithm has also been investigated to extract object features that are obscured by scattered light. Results from controlled laboratory experiments show an improvement in the range resolution and accuracy of underwater imagery relative to data collected with a conventional short pulse system.

Modulated pulse laser with pseudorandom coding capabilities for underwater ranging, detection, and imaging

Brandon Cochenour, Linda Mullen, and John Muth
Appl. Opt. 50(33) 6168-6178 (2011)

Independent component analysis for enhancement of an FMCW optical ranging technique in turbid waters

David W. Illig, William D. Jemison, and Linda J. Mullen
Appl. Opt. 55(31) C25-C33 (2016)

Spatial and temporal domain filtering for underwater lidar

Austin Jantzi, William Jemison, David Illig, and Linda Mullen
J. Opt. Soc. Am. A 38(10) B10-B18 (2021)

Resolution enhancement in active underwater polarization imaging with modulation transfer function analysis

Jiefei Han, Kecheng Yang, Min Xia, Liying Sun, Zao Cheng, Hao Liu, and Junwei Ye
Appl. Opt. 54(11) 3294-3302 (2015)

Amplitude-modulated laser imager

Linda Mullen, Alan Laux, Brian Concannon, Eleonora P. Zege, Iosif L. Katsev, and Alexander S. Prikhach
Appl. Opt. 43(19) 3874-3892 (2004)