64 THE NAVY OCEAN ENGINEERING PROGRAM 



signal, depending on the exact nature of the sea floor. A number of tech- 

 niques are being investigated which would improve the situation, including 

 space-diversity reception and detection of the leading edge of the pulse. 



Transponder navigation is the only technique which offers accuracies 

 to a few feet in deep ocean work. The beacons have both a high initial 

 cost and high replacement cost, and are susceptible to shadow zones, 

 multipath, and other interference in the transmission medium. However, 

 the technique is the best method available of relating an ocean floor to 

 geographic coordinates or relating a surface or subsurface vehicle to sea- 

 floor-referenced coordinates. 



In addition to transponders, the DSSV will use the miniature precision 

 gyrocompass and central processor developed for the DSRV. Because of 

 the stringent navigation requirements for search, an effort will be made to 

 improve these very promising systems. Navigation of unmanned vehicles 

 will be accompUshed in a similar manner. The towed vehicle can inter- 

 rogate the same navigation transponders and telemeter replies to the tow- 

 ing vessel. Compatible navigation will be essential if the DSSV is expected 

 to investigate contacts obtained by an unmanned vehicle. 



Controls 



The DSRV and DSSV will operate in a three-dimensional environment 

 and undertake a number of complicated maneuvers. On a typical rescue 

 cycle the DSRV will perform at least ten principal functions: 



• Takeoff from mother submarine (underway) 



• Navigation 



• Communication 



• Search 



• Hovering and maneuvering 



• Television/viewport viewing 



• Manipulator control 



• Mating with disabled submarine 



• Takeoff from disabled submarine 



• Landing on mother submarine (underway) 



The two DSRV operators would have a difficult time performing all of 

 these functions if separate controls and instruments were used. Thus, an 

 Integrated Control and Display (ICAD) system is being developed to co- 

 ordinate sensors, navigation, display, and controls. All sensors, navigation, 

 and propulsion equipment will provide electrical signals into the ICAD 



