The irradiance pattern was measured for the propagation of a collimated beam of light underwater. A neodymium-doubled green laser was transmitted horizontally at a six foot depth in Lake Winnipesaukee, N.H. The irradiance was measured at distances from 0 to 100 feet and for off-axis angles from 0 to 58 degrees. The water had an attenuation length of 4.54 ft/ln and an absorption coefficient of 0.0446 ln/ft. The ratio of attenuation coefficient to absorption coefficient was 4.94. The fractional power contained within a cone of various angles was computed. At 20 attenuation lengths only 10% of the total power is contained within a cone of 4 degrees whereas at 4 attenuation lengths this same cone contains 50% of the power. (Author).

It is expected that advances in optics will revolutionise the 21st century as they began doing in the last quarter of the 20th. Such fields as communications, materials science, computing and medicine are leaping forward based on developments in optics. This series presents research on optics and lasers from researchers spanning the globe.

Marine Optics

Underwater Research is primarily a review of problems in underwater viewing and hearing and acoustics. The chapters in this book are papers collated from the symposia of the Underwater Association. This book explores the need for the further study of the physiological and psychological reactions of divers. The book also concludes that diving is still the best way in studying the benthic ecology and sunken wrecks and cities. The text is divided into 25 detailed chapters. Most of the topics in the text address the common problems encountered by divers such as in hearing and viewing. Specifically, problems in diver communication, depth estimation, color distinction are some of the topics covered. Other chapters deal with the psychological reactions such as anxiety, narcosis, and visual attention. Also, some chapters tackle solutions and experiments for the improvement of diving techniques and equipment. This reference is helpful to divers, students, and scientists involved in marine and environmental science.

This volume offers a treatment of radiative transfer theory in a format tailored to the specific needs of optical oceanography, with applications to real problems. It develops the basic theory and reviews the current literature. Numerical methods for solving radiative transfer equations are then detailed, with equations describing transpectral effects, internal surfaces, and surface effects. Equations governing the propagation of visible light across air-water surfaces and within water bodies are also explained.

This textbook covers all related communication technologies of underwater wireless communication, such as acoustic communication, optical communication, and magneto-inductive communication. After describing each technology, the authors relay their pros and cons, as it is essential to learn the underlying mechanism, advancements, and limitations of these techniques. Therefore, this book provides basics fundamentals of the three technologies, their advantages and disadvantages, and their applications. The authors also introduce research trends, pointing readers in the direction of research in the field of underwater wireless communication. The book is an essential textbook for undergraduate and graduate students in the field of underwater communications. The book is also useful as a reference to undergraduate engineering students, science students, and practicing engineers. The book includes end-of-chapter questions and numerical problems.