from a minimum range of approximately two miles to a maximum range of ap- 

 proximately 20 miles with the transmitting hydrophones at a predetermined 

 depth, e.g., 25 feet. At the end of this leg the Davis changed the depth of its 

 projectors and reversed direction, traveling radially inward toward the Rexburg. 

 During the turn-around the Rexburg operator injected calibration signals from a 

 local signal generator onto the recording tape. At the conclusion of the inward 

 run the Davis changed the depth of its projectors again and traveled radially out- 

 ward once more to maximum range. This sequence of operations completed an 

 experiment in one area . Throughout this process the relative positions of the 

 ships were established by radar and communication was maintained by radio. 

 The conditions of the experiment (attenuator settings, calibration signal ampli- 

 tudes, etc.) were recorded verbally on the magnetic tape. At the Davis, the 

 operator logged the input current to the projectors and recorded their depth . 



A detailed chronology of the exercise is provided in Table A-l . Part 1 lists the 

 operations of the various ships involved; Part 2 provides the details of the acous- 

 tical experiment, including the numbering of the magnetic tapes recorded on the 

 Rexburg . The depths of the transmitting and receiving hydrophones are listed 

 in Table A -2 for each of the runs in the two areas . During operation at the first 

 site, the wind was from about 000° at about 15 knots with gusts of 20 knots . At 

 the second station, the wind was from about 340° at about 8 knots with gusts of 

 12 knots. 



A-2 



artbur ZD.IUrtlcKttr. 



