MIT/ONR OCEANIC TELESCOPE 



John M. Dahlen 



Division of Sponsored Research Staff 



Mass. Institute of Technology 



ABSTRACT 



The Oceanic Telescope is a very stable array of temperature, 

 pressure, and tension sensors located on a taut, horizontal cable 

 at 700 meters depth pointing toward the deep South Atlantic on a 

 bearing 155 true from St. Davids Lighthouse, Bermuda. The 

 purpose of this array is to observe internal waves in the main 

 thermocline, and to obtain engineering data required for the de- 

 sign of a larger scale, longer-lived future array. The taut, hor- 

 izontal cable is nearly two miles long and holds three sensor sta- 

 tions 1000 meters apart. The sensor outputs are measured, digi- 

 tized and stored on magnetic tape by a shore-based automatic 

 Data Acquisition System connected to the array by a bottom cable. 

 A schematic drawing is given in Figure 1-1. 



Installation of the Oceanic Telescope was completed success- 

 fully on 9 October, 1968. Since 2009 hours on that data a contin- 

 uous record of scientific and engineering data has been obtained. 



This paper describes the design of the Telescope, the testing 

 programs accomplished, the installation techniques employed at 

 sea, and some characteristics of the data analyzed to date. Reference 

 10 presents a complete report on the engineering program. 



Design criteria, configuration, analyses, and hardware com- 

 ponents are treated in sufficient detail to give the reader a des- 

 cription of system performance and hardware design, and an 

 appreciation for the design compromises and trade-offs involved. 

 The test program description should be of general interest as it 

 sheds some light on the quality and reliability of many components 

 and techniques which are widely used in oceanographic applications. 

 The discussion of sea installation attempts to show the relation- 

 ships between the design and the installation techniques, and the 

 precautions taken to avoid the many pitfalls which can lead to 

 loss or damage of the hardware at sea. 



This paper should be of general interest because: 



(a) It describes the full scope of activities that were in- 

 volved in transforming the Oceanic Telescope from 



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