ILLUSTRATIONS 



1 . Classification of undersea, unmanned vehicle systems . . . page 8 



2. The NOSC/USGS free-swimming submersible EAVE WEST ... 12 



3. Design 1 ; the unarmored fiber-optic element ... 18 



4. Typical yield curves for fiber-optic links ... 19 



5. Cross section of the S-glass armored fiber link . . .19 



6. The microprocessor-controlled optical fiber winding machine ... 21 



7. Design 2; the ruggedized fiber (S-glass) as wound on a deployment spool ... 22 



8. The fiber-optic deployment canister used on the EAVE WEST submersible ... 22 



9. Sensitivity of various modes to curvature ... 24 



10. Plot of spool length as a function of OD with an ID of 5 inches and cable 

 lengths of 5 and 10 km ... 25 



1 1 . Basic PFM transmission scheme ... 28 



12. Waveforms encountered in the PFM system ... 29 



13. The NOSC prototype brassboard PFM data hnk ... 3 1 



14. Block diagram of the PFM transmitter used in the NOSC PFM brassboard 

 data link ... 32 



1 5 . Block diagram of the PFM receiver ... 32 



16. Receiver operating characteristics compared with theoretical predictions ... 33 



17. Optical fiber high-pressure penetrator schematic ... 35 



18. Prototype fiber-optic penetrator (side view) ... 36 



19. Prototype fiber-optic penetrator (top view) ... 36 



TABLES 



1 . Current characteristics and capabilities of the NOSC and UNH submersibles ... 1 1 



2. Candidate tether material characteristics ... 17 



