EQUIPMENT FOR TELEMETERING OCEAN-WAVE INFORMATION 



W. A. VON WALD, JR. 



U. S. Naval Research Laboratory 



Washington 25, D. C. 



INTRODUCTION 



Wave measurements in mid-ocean have been 

 plagued "by three main obstacles: (l) observers 

 generally do not agree on wave height (and also 

 tend to ignore wave period), (2) in heavy seas 

 the main emphasis of a ship captain is on sur- 

 vival rather than on measurements and (3) instru- 

 mentation for shipborne wave measurements is not 

 generally available. Further, survey vessels 

 that are equipped with wave-measuring instruments 

 are not likely to provide sufficient data to 

 describe the wave climate. An unmanned buoy that 

 could measure ocean waves, particularly if it 

 could do this on a currently-reporting basis, 

 would seem to be a valuable asset to oceanographic 

 instrumentation. 



THE WEATHER BUOY 



The United States Naval Research Laboratory, 

 has developed a weather-telemetering buoy (shown 

 in Fig. l) designed to transmit wind speed, wind 

 direction, barometric pressure, air temperature 

 and water temperature at 6-hour intervals . The 

 messages are sent in Morse Code with numerous 

 "repeats." Provision has been made to add up to 

 5 information channels without modifying the 

 equipment and an additional 5 channels after minor 

 modification. These added channels have been pro- 

 vided for telemetering outputs of oceanographic 

 sensors that may be available in the future. 



The buoy case is 36 inches in diameter and 

 30 inches high. A telescoping ballast structure 

 extends 15 feet below the buoy. A telescoping 

 superstructure with an l8-foot whip antenna ex- 

 tends above the buoy. All external instrumenta- 

 tion is mounted in a single assembly on top of 

 the antenna. A UHF beacon is provided to permit 

 aircraft to locate the buoy or, if the buoy is 

 moored, permit its use as a navigational aid. 

 The buoy weights 600 pounds and carries batteries 

 for 12 months of unattended operation. 



Inside the buoy case a lower compartment houses 

 the batteries . The instrumentation for coding, 

 programming and measuring barometric pressure, 

 station direction and average wind speed are 

 located in the upper portion. Also in the upper 

 compartment are a dc-dc convertor, 2 transmit- 

 ters, 2 command receivers for remote turn-on. 

 On clock-control one frequency is used in the 



Fig. 1. The weather buoy. 



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