The factors contributing to the visibility of submerged targets are discussed and the data requirements for calculating submerged contrast and contrast transmittance are developed. An instrument capable of making the measurements of the optical properties of seawater needed for visibility calculations is described. The instrument incorporates proven features of previous spectral transmissometers and oceanographic illuminometers into a single unit that can be operated through standard STD cables up to 8000 meters in length. It can, as a result, be used on most oceanographic vessels without requiring the addition of a special winch and cable. The instrument system utilizes a unique microprocessor-controlled, digital data acquisition and command system. This system performs the control and data transmission functions for eight underwater data channels through the armored, single wire STD cable. The total instrument system includes an HP9830B desk-top computer for data processing and recording, with an interconnected plotter for the real-time plotting of the measured variables.

Date Published: 10 November 1978
PDF: 14 pages
Proc. SPIE 0160, Ocean Optics V, (10 November 1978); doi: 10.1117/12.956852

Published in SPIE Proceedings Vol. 0160:
Ocean Optics V
Matthew B. White; Robert Stevenson, Editor(s)