Integrating optics and sonar for a deeply towed vehicle

Geophysical surveys of the deep sea floor often require the combined use of optical systems for high resolution and sonar systems for broad areal coverage. Combining such systems in a single vehicle requires the consideration of numerous trade-offs.In the Deep-Tow system of the Marine Physical Laboratory, several sonar and optical systems are operated by means of an armored coaxial tow cable to depths in excess of 7 km. Power, control signals and data are multiplexed on the single coaxial conductor of this cable.Incorporated in this survey system are side-scan and high-resolution profiling sonars; together with stereo 35 mm film, and slow-scan television cameras. The television system operates in a "snap-shot" manner, with greatly reduced bandwidth and low,power consumption through the use of strobe lighting and scan conversion. This paper reviews the development of these systems as well as some of their applications and results.