152 • Marine Minerals: Exploring Our New Ocean Frontier 



Photo credit: U.S. Geological Survey 



Underwater camera system, ready for deployment 



ment. These include, but aire not limited to, broader 

 bandwidths for television signals, greater manipula- 

 tive dexterity and sensory perception, and more 

 precise station-keeping and control of the vehicle 

 itself. The advent of the microprocessor has intro- 

 duced other candidates: artificial intelligence, pat- 

 tern recognition, teach/learn programs, greater 

 memory, all of which can serve to improve the ca- 

 pability of the vehicles and their accompanying sen- 

 sors and tools. There is no question that these 

 aspects of vehicle technology are worthy of consid- 

 eration and that they will undoubtedly improve our 

 underwater exploration capability. But before ad- 

 ditional development or improvement of undersea 

 vehicle technology for EEZ hard minerals explo- 

 ration begins, it may be more important to assess 

 fully the applicability of the currendy available tech- 

 nology. 



Optical Imaging 



Optical images produced by underwater cameras 

 and video systems are complementary to the images 

 and bathymetry provided by side-looking sonars 

 and bathymetry systems. Once interesting features 



have been identified using long-range reconnaissance 

 techniques, still cameras and video systems can be 

 used for closeup views. Such systems can be used 

 to resolve seafloor features on the order of 10 centi- 

 meter to 1 meter. The swath width of imaging sys- 

 tems depends on such factors as the number of cam- 

 eras used, the water characteristics, and the height 

 of the imaging system above the seafloor. Swaths 

 as wide as 200 meters are currently mappable. 



ANGUS (Acoustically Navigated Underwater 

 Survey) is typical of many deep-sea photographic 

 systems. Basically, ANGUS consists of three 35- 

 millimeter cameras and strobe lights mounted on 

 a rugged sled. The system is towed approximately 

 10 meters off the bottom in water depths up to 6,000 

 meters (19,700 feet), and is capable of taking 3,000 

 frames per sortie. It has been used in conjunction 

 with dives of the submersible Alvin . 



A newer system, currently under development 

 at the Deep Submergence Laboratory (DSL) at 

 Woods Hole Oceanographic Institution, is Argo. 

 On her maiden voyage in September 1985 Argo 

 assisted in locating the Titanic. Like ANGUS, Argo 

 is capable of operating in water depths of 6,000 

 meters. Argo, however, is equipped with a wide- 

 area television imaging system integrated with side- 

 looking sonar." It currently uses three low-light- 

 level, silicon-intensified target cameras (one for- 

 ward-looking, one down-looking, and one down- 

 looking telephoto), extending the width of the im- 

 aged swath to 56 meters (184 feet) when towed at 

 an altitude of 35 meters. 



Argo is being designed to accommodate a sec- 

 ond ROVs, to be known as Jason. Jason will be 

 a tethered robot capable of being lowered from Argo 

 to the seafloor for detailed camera (and sampling) 

 work (figure 4-13). Its designers plan to equip Ja- 

 son with stereo color television "eyes."'' One cur- 

 rent limitation is the lack of availability of an ade- 

 quate transmission cable for the color television 

 pictures. Color television transmissions exceed 6 

 million bits per second, and large bandwidth ca- 

 bles capable of carrying this amount of informa- 

 tion have not yet been developed for marine use. 

 Fiber-optic cables are now being designed for this 



"S.E. Harris and K. Albers, "Argo: Capabilities for Deep Ocean 

 Exploration," Oceanus, vol. 28, No. 4, 1985/86, p. 100. 

 "R.D. Ballard, "Argo-Jason," Oceans, March 1983, p. 19. 



