Lidar-radar heterodyne receiver for underwater imaging applications Navy SBIR FY2008.1 Sol No.: Navy SBIR FY2008.1 Topic No.: N08-032 Topic Title: Lidar-radar heterodyne receiver for underwater imaging applications Proposal No.: N081-032-0469 Firm: Radiation Monitoring Devices, Inc. 44 Hunt Street Watertown, Massachusetts 02472 Contact: Madhavi Seetamraju Phone: (617) 668-6824 Web Site: http://www.rmdinc.com Abstract: High spatial resolution, LIDAR images of underwater targets from air and submersed platforms are plagued by poor signal-to-noise ratios (SNR), arising from strong scattering in the turbid media of seawater. A hybrid system that combines the detection and coherent signal processing techniques of conventional RADAR with the optical propagation characteristics of LIDAR improves target detectability and image contrast. For this application the receiver should have a good response at the RF modulation frequency of 1 GHz and a large dynamic range to detect return signals from deep targets in highly scattering waters. Radiation Monitoring Devices, Inc. (RMD) proposes to develop an avalanche photodiode (APD) based receiver system to increase the SNR by at least ten fold and the dynamic range by more than 20 dB over existing PMT based receiver modules. The novel receiver will operate on gain modulation and heterodyne detection techniques in order to offer improved system response at the required high modulation frequency (~1 GHz). By leveraging previous experience with high performance receiver systems, RMD's highly qualified research team will design, fabricate and deliver an APD-based receiver module with ~ 1 GHz bandwidth, ~ 60dB dynamic range and a superior SNR to NAVAIR for evaluation. Benefits: The main application for the proposed hybrid LIDAR-RADAR receiver is remote sensing and imaging through turbid media. This includes underwater and atmospheric surveillance for both defense and domestic applications. Benefits include the detection and identification of fish schools, submarines, underwater mines and obstacles; in nautical or waterway mapping. In addition, atmospheric studies will benefit improved standoff evaluation of cloud properties and pollutants. These non-ionizing optical techniques also have benefits to the medical field for imaging through the highly scattering human tissue. Applications include detection, diagnosis and treatment of cancerous tumors and in monitoring blood constituents. Return