62 THE NAVY OCEAN ENGINEERING PROGRAM 



trace of returns parallel to the DSRV axis, and the athwartship scan will 

 give a trace of the contour in the perpendicular direction. Near the dis- 

 abled submarine the DSRV pilot will switch to the 1 5 ft high-definition 

 scale to attempt to determine features on the submarine hull. 



If visual contact is made with the submarine, then the DSRV's TV 

 cameras and lights will be used in place of the short-range sonar. During 

 the final stages of mating and hauldown on the submarine hatch, the for- 

 ward pan-and-tilt assembly with its TV camera can view the submarine 

 hatch area and the DSRV's manipulator. Another TV camera will be 

 located in a porthole in the mating skirt, and a second pan-and-tilt unit 

 will be located aft of the mating skirt. The pilots will have the choice of 

 using any of these TV cameras or remote-viewing optics to look directly 

 out the viewports. 



In addition to the doppler sonar, the DSRV will have a miniature 

 precision gyrocompass to provide an accurate indication of heading. This 

 is a three-axis system, using three integrating gyros and two accelerometers 

 as its sensors. This compass can furnish attitude information for the sub- 

 mersible's stabilization system, provide a reference for computation of 

 velocities from the doppler system, and provide position information by 

 operating as a miniature inertial system. 



Computations for the various navigation modes are performed in a 

 central processor. This computer has both digital differential-analyzer and 

 general-purpose subsections. A wide range of signal processing and com- 

 putation can be accomplished by the computer, relieving the operators of 

 many of the more time-consuming or difficult aspects of navigation. Pre- 

 launch check out is also performed in large measure by the computer. As 

 an alternate to dead reckoning and homing, the DSRV can navigate by 

 means of transponders dropped from the support ships and homing trans- 

 ponders carried by the rescue submersible itself. 



Once the DSRV has located the disabled submarine, the submersible 

 will be able to release one or two homing transponders to facilitate return 

 to a precise position. A tracking transponder in the DSRV will home in 

 on the expendable transponder. 



The Deep Submergence Search Vehicle will carry out its coordinated 

 search tasks while navigating with respect to one or more transponders, 

 usually deployed from a support vessel. The transponders can be used 

 either singly to reset a dead reckoning navigator or in groups as shown in 

 the drawing. Groups of transponders are usually placed in rectangular pat- 

 terns, one to three miles apart. Position fixes are obtained by range 



