Interview Program 



The questionnaire- interview pilot survey program was contracted to 

 Chambers Consultants and Planners. The work on this program was initiated on 

 1 August 1980, and the first draft of the questionnaire and the instructional 

 material were reviewed by NOSC in September 1980. 



Instrumentation . A state-of-the-art recording system was selected, 

 purchased, and assembled with the following properties: 



Recording and Measurement of Source Data 



Instrumentation . A state-of-the-art rect 

 hased, and assembled with the following i 



• Hydrophone: B&K Type 8101 with useful frequency range from 1 Hz to 125 

 kHz. 



• Pre-amplif ier and Filter: Ithaco Model 451 Data Acquisition Amplifier 

 with gain adjustable in 1 dB steps, and low frequency rolloff selectable to 1, 

 10, 100, Ik, and 10k Hz. 



• Magnetic Tape Recorder: Nagra Model TI, twin capstan instrumentation 

 tape recorder, with four tracks, speed adjustable in 8 steps from 15/32 to 60 

 inches per second (ips). Frequency response is to 10 kHz in the FM mode and 

 0.1 to 125 kHz in direct mode at 30 ips. Normal operating speed is 7.5 ips, 

 which provides a frequency coverage of to 2500 Hz on the FM channel and 0.1 

 to 30 kHz on the direct channel. Both channels are recorded simultaneously to 

 provide frequency coverage from to 30 kHz. 



The above system is capable of battery operation for field measurement, 

 and may be packaged for ready transportation to field locations by air 

 transport, boat, and/ or helicopter. The hydrophone is equipped with 300 feet 

 of cable and may be suspended from a special float system for stabilizing 

 vertical motion. 



Field Measurements 



Tape recordings have been acquired for six different platforms located in 

 three geographic areas: Santa Barbara, California; Cook Inlet, Alaska; and 

 Atlantic City, New Jersey. General information on each is summarized below: 



1. Santa Barbara-Ventura, California, April 1980 . 



Platform Holly --ARCO production/drilling platform, 2-1/2 miles off 

 shore from Goleta, California in water of 211 feet. The platform is supported 

 on eight hollow steel legs driven into the ocean floor and filled with 

 concrete. Prime power is supplied by diesel engines with mufflers. 

 Measurement-, included airborne, structureborne, and underwater sound. 

 Underwater measurements were made overside from a drifting boat. Underwater 

 recordings utilized an interim system which did not achieve the high gain, 

 wide bandwidth capability of the NOSC-developed system described above, and 

 used at other locations. Measurements were made during production, drill 

 pulling, and dyna drilling operations. Production was approximately 6000 

 barrels per day and drill depth, 850 feet. 



E-3 



