226 OCEANOGRAPHY IN THE UNITED STATES 



ing from a set of our wiring diagrams, developed a wave buoy almost identical 

 with ours, which is now in operation. 



We are satisfied that our instrument is not only useful for our problems but 

 has some appeal as a standard oceanographic instrument. 



OCEANOGBAPHIC SURVEY INSTRUMENT 



(By J. J. Nelligan) 



Considerable interest has been shown in an underseas weapon evaluation 

 activity by the Office of Naval Research, the Bureau of Ships, and the Bureau 

 of Ordnance. The possibility of combining a system of hydrophones and an air- 

 tracking network that could be used for weapon evaluation as well as acoustic 

 evaluation of ships and submarines holds great potential. Since the oceano- 

 graphic information necessary to design and install such a range is not available, 

 it was necessary to design and construct a device for this specific purpose. 



On oceanographic survey instrument is being developed to provide a means of 

 measuring ocean currents at great depths. Ultimately, it is expected that the 

 instrument will measure the speed (from 0.1 to 5.0 knots) and direction of cur- 

 rents, water temperature, pressure, degree of salinity, and the speed of sound 

 at various depths down to 10,000 feet below the surface. 



This first protoype is being instrumented to measure only current speed and 

 direction, water pressure, and temperature. Now in the development and test 

 stage are two methods of measuring current speed ; A strain-gaged cantilever 

 flexure, sensitive to the drag force produced by flow past a flat plate, and an 

 a.c. powered magnetic log which utilizes the electrical conducting properties of 

 water. The flexure system has been tested in the basin and appears to have 

 the necessary sensitivity at very low speeds. The speed-sensing devices are 

 mounted in the free flooding nose section of the model. The construction of a 

 magnetic compass to provide measurement of current direction is nearing 

 completion. 



The various measurements are transmitted to the receiving station on the 

 surface through a single conductor cable on a cyclic basis by means of telemeter- 

 ing cii-cuitry housed in the cylindrical pressure vessel. The original circuitry 

 incorporated in the model and tested at sea last November has been simplified in 

 design, and the revised design is now under construction. It is expected to be 

 ready for basin tests by May 1. 



Calibration of the instrument will be completed in the DTMB deep water 

 basin in May prior to sea trials in the Tongue of the Ocean, Bahamas, in June. 



The Roi.e of the Applied Mathematics Laboratoey 

 IN THE Solution of Oceanographic Problems 



(By J. W. Wrench, Jr.) 



Two basic problems have confronted oceanographers as their research has 

 broadened its scope through the use of far-ranging research vessels and ingenious 

 instruments for extracting information from the sea, in fulfilling the need and 

 desire to know more of the physics, chemistry, and biology of the oceans. The 

 first of these problems is simply how to reduce huge volumes of oceanographic 

 survey data and to present the results in a form that can be made generally 

 available to scientists who require certain information on the structure and 

 behavior of the oceans. The second problem involves the performance of thou- 

 sands and even millions of arithmetical operations on a set of oceanographic 

 data in order to extract therefrom information about the sea. It is easy to see 

 tliat oceanographic research would soon bog down if liigh speed computational 

 facilities were not available for these mammoth tasks. 



The Applied Mathematics Laboratory of the David Taylor Model Basin is 

 equipped for the handling of just such problems. At present our basic facilities 

 include a Univac and an IBM 704, which is seven times faster than Univac in the 

 solution of such problems. Preparations are being made for installation of a 

 LARC, which is faster yet. Such machines are capable of handling the type 

 and volume of data collected by oceanographers. 



