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Advanced Underwater Imaging. James M. Glynn <glynn@psicorp.com> 10 October 2008. Advanced Underwater Imaging Program Overview. A combined hardware/modeling/experimental effort to develop a novel pulsed laser line scan (PLLS) imager
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Advanced Underwater Imaging James M. Glynn <glynn@psicorp.com> 10 October 2008
Advanced Underwater Imaging Program Overview VG00- • 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)
Highlights VG00- • 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
Novel Scanner Design VG00- • 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
High Rep Rate Pulsed 532 nm Laser VG00- • Development at PSI/Q-Peak • 2.5W average power, 7 nsec pulses, 350 kHz • Enables pulsed gating of target return for backscatter rejection
Extended Underwater Imaging Test Facility VG00- • Unique underwater imaging test facility at HBOI • 13 x 7 x 2 m, moving seabed simulator, optical property adjustment and measurement, optics lab
New Pulsed Laser Modeling Codes VG00- • 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
Pulsed Laser Performance Modeling – Image Simulation VG00- User sets operational, environmental, system, and target parameters
CW – PLLS Imaging Experimental Comparison VG00- CW PLLS 0.6 AL 5.1 AL
CW – PLLS Imaging Comparison VG00- PLLS 0.6 AL 5.1 AL
Summary VG00- • 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