SEACLIFF dove at 1300 local time on 9 December 1976. Eight slow-scan transmissions 

 were made on that day at depths ranging from 900 ft to the bottom at 3755 ft. On the next 

 day SEACLIFF dove at 0835 and an additional five slow-scan transmissions were made. Table 

 5 lists the SEACLIFF transmissions by type and depth. 



TABLE 5. SEACLIFF SLOW-SCAN TRANSMISSIONS - 

 DEC9& 10, 1976 



Transmission No. 



Depth, ft 



Procedure 



1 



900 



B 



2 



950 



B 



3 



1000 



B 



4 



3755 



B 



5 



3755 



B 



6 



3755 



B 



7 



2000 



C 



8 



2000 



C 



9 



1000 



B 



10 



1000 



B 



11 



1000 



B 



12 



1000 



D 



13 



3500 



C 



In order to reduce multipath interference it was desirable to have the MAXINE D 

 position herself as nearly vertically above the SEACLIFF as possible. The MAXINE D 

 had a short baseline system which was, in principle, capable of providing the necessary posi- 

 tioning information. However this gear was not operational during the SUBSAT tests. Inter- 

 mittent slant range information was available, however, although receipt of this information 

 did not always coincide with a slow-scan transmission. Best estimates are that there was a 

 horizontal separation between SEACLIFF and MAXINE D of 400 to 1300 yards. If so, 

 most of the slow-scan transmissions took place with the direct path outside the main lobe of 

 the sending and receiving transducers. 



2.3 DOLPHIN EXPERIMENT 



In early January the NOSC SUBSAT team was advised that the deep-diving submarine 

 DOLPHIN would be transiting from San Diego in late January and the possibility existed 

 for additional SUBSAT tests. A test plan (Appendix B) was devised for rendezvous with the 

 DOLPHIN off San Clemen te Island with NOSC's Box L boat as the surface vessel. The 

 DOLPHIN would proceed to make a series of straight-line passes designed to pass directly 

 beneath the Box L boat. NOSC civilian personnel aboard both boats would originate and 

 receive the slow-scan transmissions at various points along each pass. 



Equipment installation on the Box L and DOLPHIN was completed by 21 January. 

 The DOLPHIN setup was very similar to that on SEACLIFF, with camera, monitor, recorder, 

 and Robot 400 being brought aboard and interfaced with each other and the DOLPHIN'S 

 ATM504A UQC. Since the Box L had no UQC, an ATM504A was installed there in addition 

 to the slow-scan equipment. Two SP23LT conical transducers, one with baffle and one with- 

 out, were taken aboard. Using each transducer at depths of 20 and 200 ft would allow four 



12 



