Various methods now exist for converting original data to a medium 

 suitable for direct input into data processing equipment: (1) keypunching 

 of EAM cards from original source documents, (2) converting punched 

 paper tape to punched cards, (3) direct punching of paper tape, (4) use- 

 of off-line computer equipment such as punched card-to-magnetic-tape 

 converters or magnetic tape-to-line print-out, (5) use of universal data 

 translators to convert analog or digital magnetic tape to other digital 

 magnetic tape, (6) use of special purpose translator devices, and 

 (7) use of an electronic computer as a data medium translator for 

 card- to- magnetic-tape or magnetic tape-to-line print- out. This last 

 method is usually very costly; however, some computers (e.g. inter- 

 mediate class) can do this economically on an extra shift rental basis. 



For the present, the problem is reduced to that of either recording 

 all data on punched cards or tape, or of providing a suitable means of 

 converting from the form of the original record to punched cards or 

 tape. For many purposes, punched cards will be the best means for 

 tabulating or computing data; for other purposes, these will have to 

 be converted to computer magnetic tape. During the past few years 

 a number of instruments have been developed that can relatively 

 inexpensively convert analog data to digital data, either coded or 

 uncoded. A typical example of how this could be accomplished with 

 Hydrographic Office data is described below. 



Assume that sea temperature information is recorded on magnetic 

 tape in terms of a varying audio frequency. When this magnetic tape 

 is played back through a digital frequency counter with a ten-line 

 output, and the output of up to five decimal digits is scanned with a 

 scanner- coupler connected to a card punch, the temperature informa- 

 tion will be digitally punched in terms of frequency or in terms of 

 degrees, if the calibration is computed into the system. 



The foregoing example is a relatively simple one. However, a 

 number of other instruments are available that will allow d.c. sensing 

 elements to enter this same system. Scanner- couplers can be modified 

 to scan up to six six-digit counters and can be coupled to a card 

 punch, paper tape punch, or printer in various codes. These modifica- 

 tions typically cost a few hundred dollars each. 



E. SEA WATER TEMPERATURE MEASUREMENTS 



No other instrumental oceanographic measurements are so widely 

 taken as those of sea temperature. Although efforts are made to con- 

 trol the accuracy of these observations by screening them prior to 

 their incorporation into data files, accuracy is far below that desired. 



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