into three problem areas: First, buoys designed for use in incor- 

 porated systems; second, sensors for each parameter to be mea- 

 sured; and third, ultimate data recording. 



Although considerable work and study have been expended to- 

 ward developing various buoy applications, very little has been 

 done toward implementing a system capable of operating at pre- 

 determined intervals for long periods of time. Dr. William S. 

 Richardson, Woods Hole Oceanographic Institution, is presently 

 engaged in such a program and has much information on the prob- 

 lems involved. In addition to solving the problems of environmen- 

 tal deterioration resulting from the marine biology, stress, etc., 

 encountered, planting and recovery methods must be improved and 

 greater insurance provided for the overall system to withstand ex- 

 treme sea states. Recent developments by industry of new alloys 

 and plastics which have considerable resistivity to environmental 

 deterioration and greatly improved strength-weight ratios surely 

 will aid in this instrumentation problem. 



The second category is the development of sensors. Most 

 sensors used today for procuring oceanographic data have been 

 developed by industry for other applications and, through modifi- 

 cations, have been adapted to serve our purpose. As a result, the 

 attendant problems of preventing deterioration by corrosion, of 

 being able to withstand severe ocean pressures, of remaining 

 stable at different depths for long periods of time, and of possess- 

 ing the required resolution have resulted in the incorporation of 

 complex electronics in an attempt to approach our requirements. 



Present sensors leave much to be desired. A discussion of 

 them often results in controversy as to the best approach. Basi- 

 cally, sensors can be characterized as mechanical or electro- 

 mechanical. The mechanical type utilizes delicate parts to ob- 

 tain the required resolution, and, therefore, is not practical for 

 buoy or rough weather usage. The electromechanical type can 

 be subdivided into three classes: Analog, digital, and variable 

 frequency (FM). Although the digital and variable frequency sys- 

 tems may be analog in origin, for comparison they will be dis- 

 cussed separately. Analog systenns, by their very nature, require 

 environments which permit extremely stable operation since any 

 degree of allowed instability results in error in the ultimate data. 

 Generally the dynamic range of an analog system is restricted. 

 Any improvement can only be accomplished by the use of very com- 



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