different receiving conditions to be tested. A 4- to 6-kHz noise source was brought aboard 

 Box L to serve as a beacon for DOLPHIN to align itself on prior to beginning a run. In 

 addition, a 9-kHz acoustic pinger system was installed aboard Box L and DOLPHIN. Prior 

 synchronization of these units with WWV would, in principle, allow continuous measurement 

 of slant range between these two platforms. 



Box L left San Diego on 24 January for Wilson Cove, San Clemente Island, where it 

 spent the night. DOLPHIN left San Diego with NOSC SUBSAT personnel aboard later that 

 day for its rendezvous with Box L the next morning off San Clemente Island. Box L left 

 Wilson Cove at 0600, 25 January and rendezvoused with DOLPHIN off the southeast coast of 

 San Clemente Island. DOLPHIN dived in 2620 ft of water at 0825. 



At 0923 DOLPHIN was at one-half test depth, the desired operating depth, and 

 began her first run. The actual test depths of DOLPHIN are classified and therefore all depths 

 are referred to here as fractions of test depth. At 1000 it became evident to DOLPHIN 

 personnel that DOLPHIN was not on the right course, and she requested Box L to put the 

 broadband noise source in the water. At 1020 a second run was begun and two slow-scan 

 transmissions were made. Since the slant range to DOLPHIN was opening rather than closing, 

 this run was aborted after the second transmission. At 1045 DOLPHIN turned to begin its 

 third run. Four video transmissions were made and again indications were that the range was 

 opening rather than closing, since the transmission which was supposed to have occurred at a 

 horizontal range of ft actually occurred at a horizontal range in excess of 5000 ft. Two 

 more runs were attempted, the second of these at one-quarter test depth. Although the CPA 

 of these runs came closer to directly below the Box L, it was evident from voice range marks 

 and the variation of the received signal strength that even these runs occurred at a consider- 

 able horizontal offset. The test ended at 1310. 



A total of 13 slow-scan transmissions were made and received during the DOLPHIN 

 tests. All transmissions were received with the baffled hydrophone at a depth of 200 ft, since 

 there were not enough close-in runs to compare different hydrophones and depths. Although 

 a TV camera was provided aboard the DOLPHIN, all transmissions were from pre-recorded 

 tape (see Procedure B, Appendix A). 



Post-exercise debriefing of personnel aboard DOLPHIN revealed that neither the 9-kHz 

 pinger nor the 4- to 6-kHz noise source could be used as intended. Throughout the exercise 

 no valid range reading could be obtained from the 9-kHz pinger, and the only range information 

 available was from intermittent and relatively inaccurate oral time marks. The broadband 

 noise source apparently suffered from multipath, and this — coupled with other noise sources 

 in the vicinity (i.e., a fishing boat) — led to grossly inaccurate bearings on the first three 

 passes. The last two passes apparently began on the proper headings, but from the measured 

 ranges near the end of the runs it was apparent that DOLPHIN did not pass directly beneath 

 Box L. Thus, just as in the SEACLIFF experiment, most acoustic transmissions from 

 DOLPHIN were at angles far from the vertical, that is, far from the main lobe of the sending 

 and receiving transducers. 



3. RESULTS 



3.1 EXAMPLES OF SUBSAT VIDEO 



A total of 26 video transmissions, each consisting of a number of pictures, were sent 

 and received during the DOLPHIN and SEACLIFF operations. Although each picture was 



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