1. Physical Sciences Inc. (978) 689-000320 New England Business CenterAndover, MA 01810 Advanced Underwater Imaging James M. Glynn 10 October 2008

2. VG00- Advanced Underwater Imaging Program Overview  A combined hardware/modeling/experimental effort to develop a novel pulsed laser line scan (PLLS) imager –Imaging at longer ranges in turbid water than a conventional CW laser line scan, in a more compact hardware package –Reduce size and power requirements to enable implementation in compact unmanned underwater vehicles (UUV’s)

3. VG00--2 Highlights  New hardware –Folded scanner geometry –High power, high rep rate, short pulse laser  New imaging test facility –Large scale test tank with controlled illumination and water optical properties  New performance modeling capability –Laser pulse time history –Pulsed laser image simulation  Experimental validation of hardware and model performance

4. VG00--3 Novel Scanner Design  Folded scanner geometry enables use of single rotating polygon for transmit and receive  Results in more compact design, enabling UUV configurations  Prototype functioning at HBOI

5. VG00--4 High Rep Rate Pulsed 532 nm Laser  Development at PSI/Q-Peak  2.5W average power, 7 nsec pulses, 350 kHz  Enables pulsed gating of target return for backscatter rejection

6. VG00--5 Extended Underwater Imaging Test Facility  Unique underwater imaging test facility at HBOI  13 x 7 x 2 m, moving seabed simulator, optical property adjustment and measurement, optics lab

7. VG00--6  Developed by Metron Inc. as a variant of their EODES-3 CW laser line scan performance prediction model  Time history of laser pulse in water –Backscatter and target returns from both laser and solar energy  Image simulation –Predicted image quality as a function of user-settable parameters  Validated against experimental data  Use the model as a design aid New Pulsed Laser Modeling Codes

8. VG00--7 Pulsed Laser Performance Modeling – Image Simulation User sets operational, environmental, system, and target parameters

9. VG00--8 CW – PLLS Imaging Experimental Comparison CWPLLS 0.6 AL 5.1 AL

10. VG00--9 CW – PLLS Imaging Comparison PLLS 0.6 AL 5.1 AL

11. VG00--10 Summary  New enabling hardware has been built and tested in new large-scale imaging test facility  New modeling capability to support design has been validated through comparison with full-scale experiments  The pieces are in place to proceed to a targeted development effort for a pulsed laser line scan in a UUV-compatible package