Adequacy of Existing Equipment 



105. Available geophysical equipment and techniques are, in general, 

 adequate for borrow source exploration. Research and engineering efforts to 

 improve basic equipment are continually undertaken by manufacturers, and sev- 

 eral improvements such as swell filters and automatic gain control have been 

 developed over the years. Given the physical factors involved in geophysical 

 survey methods, it seems unlikely that elemental changes in the existing sys- 

 tems will be made in the foreseeable future; further advances in the technol- 

 ogy will probably be in the nature of improvements to the design and 

 engineering of existing basic system components and computer analysis of data 

 leading to improved record quality. 



106. Of the possible improvements that would be of benefit, the most 

 desirable are increased economy of operation, flexibility, noise reduction and 

 suppression of false reflectors known as multiples, and an increase in the 

 ability of seismic reflection profilers to penetrate difficult material with- 

 out excessive loss of resolution. Greater economy of operation could be 

 achieved by an increased ability to function under unfavorable weather condi- 

 tions and operate at higher survey speeds with consequent reduction of 

 downtime and increased daily trackline mileage. The equipment most sensitive 

 to weather conditions and survey speed is the seismic reflection system. 

 Present capabilities for towing the acoustic source and receivers well below 

 the surface can considerably reduce wave motion effects and extraneous acous- 

 tic noise associated with towing these components on the surface. However, 

 given the depth range to which borrow source exploration programs are limited, 

 the water would be too shallow in many areas for effective use of submerged 

 vehicles . 



107. Because of the often highly variable geologic conditions found in 

 coastal areas, flexibility is a valuable feature in geophysical systems used 

 for borrow source exploration. Selective control of such features as scale 

 and frequency range are integral parts of existing equipment. Tape-recording 

 of raw acoustic signals greatly increases flexibility by allowing subsequent 

 playbacks using different control settings to obtain optimum record quality. 

 Increased control of output power levels is one area in which increased flexi- 

 bility could be achieved by enabling record monitors to make rapid variations 

 in output power to adjust to rapidly changing geological conditions. 



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