Deep sea telemetry system for sediment analysis

A telemetry system that can communicate with a deep ocean sediment probe in depths of up to 6,000 feet from a shipboard location is described. Data from the probe occupies a total bandwith of over 200 Khz so that transmission through the ocean is immediately ruled out. The transmission medium chosen is 10,000 feet of type 2P4ORC double armored coaxial cable that also acts as the load bearing number. The attenuation characteristics of this cable are plotted. It is apparent from this plot that a modulation technique that is independent of amplitude distortion should be used. An FM technique, which transmits 100 channels of data --2 of which have bandwidths of 100 Khz, is used to obtain distortionless information that is recorded aboard ship on magnetic tape. Commands are initiated at the shipboard Control Console as oscillator pairs. The two frequencies have tuned devices on the probe which decode the pair. Commands and data can be transmitted simultaneously.