The invention in this proposal provides significant improvements for uncooperative submarine periscope detection and identification through the development of a hybrid multi-mode sensor, consisting of a combined direct-detection imaging flash lidar and a micro-Doppler coherent lidar that would dramatically enhance the effectiveness of operational airborne mission instruments. The lidar solution proposed will have a large field-of-view (FOV) active imaging sensor for basic, yet fast, object detection, a high-power transmitter for long range capability, an electro-optical beam steering aperture for a larger collection area/small volume and reliability, and a highly sensitive active interrogation sensor for false alarm mitigation and target identification. While the optical signal and receiving detector(s) are different for the two technologies, significant overlap of components can exist if carefully designed; e.g., common scanner, pump lasers, signal processing hardware, and thermal management. The focus of this project will be to provide a lidar where the wide-beam (near) photon-limited direct detection flash lidar acquires detections and very quickly, in-turn the narrow-beam coherent detection lidar is directed to the detection position to interrogate and confirm/reject those detections as periscope targets. This track-while-scan system with the potential to provide on-location target identification has the ability to be a game-changing US military asset.
Benefit: The capabilities and benefits of this technology is improved operational knowledge beyond generic imaging. Uncooperative target identification (via vibrometry) through the use of coherent lidar micro-doppler has been sought out for operational use for decades. Most of the programs have focused on ground vehicles. This program would open the field of naval stand-off target identification. Other potential applications for the hybrid lidar technology includes helicopter obstacle avoidance, airborne threat/battlefield assessment, non-cooperative IFF, air-data, landing, etc. In the last decade numerous military helicopters damaged by hitting obstacles or weather conditions. Aligned with obstacle avoidance is the capability of the coherent detection to support the ability to sense wind speed (horizontal and vertical), wind shear, micro-bursts, close formation rotary-wing downwash and turbulence. Potential non-DoD commercial applications for the hybrid lidar include helicopter obstacle avoidance and ground vehicular collision avoidance. With the combined 3D imaging capability of the flash lidar and the high sensitivity of coherent lidar, detection/false alarm performance can deliver a system that helicopters and other aircraft can use reliably. As the operational region and altitude for larger UAVs increase, they will be faced with the same natural and man-made threats as current manned helicopters, but have less capability to avoid unpredicted events, e.g., clear air turbulence. Lidar is a key technology for vehicular collision.
Keywords: micro-doppler vibrometry, micro-doppler vibrometry, signature identification, Hybrid Lidar, LADAR, flash-lidar, Coherent laser radar, photon limited direct detection, non-cooperative IFF
