Long-Range Passive Surveillance in Anti-Access/Area-Denial Environments

The U.S. military historically relied on active, monostatic radar for long range, noncooperative detection and localization of targets. Our adversaries counter this capability by exploiting radar emissions, which reduces the effectiveness of monostatic radar and makes U.S. platforms vulnerable to engagement. Passive bistatic radar (PBR) architectures that exploit existing transmitters in the environment, i.e., illuminators of opportunity (IO), were developed to enable covert target surveillance and increase resilience to jamming, at a lower overall SWAP-C compared to monostatic systems. PBR systems utilize as illuminators numerous transmitters for telecommunications, radionavigation, FM radio, digital video broadcasting-television (DVB-T), cellular base stations employing GSM or LTE, Global Positioning System (GPS), as well as LEO/GEO satellite transmissions. This SBIR topic will develop a passive bistatic radar architecture leveraging SIGINT receiver technology leading to a more global, persistent, resilient, and robust long range surveillance capability for the Navy. Incorporating SIGINT receivers into PBR architectures provides a number of advantages including: wide operational bandwidth supporting simultaneous IO collection leading to greater flexibility and utility, multi-element apertures each with a wide instantaneous field of view that eliminates issues with scan-on-scan or pulse chasing for directional transmitters/receivers in traditional systems, and more complete data capture over whole anticipated parametric range enabling growth with future IOs. Azure Summit Technology, Inc.’s (Azure's) solution leverages Azure innovations as well as capabilities and technology components developed in our current and prior efforts with the Navy, Air Force, and other agencies: -Azure’s modular, scalable, and flexible Switchblade Low SWaP-C Intelligent Digital RF Transceiver family is the basis for PMA-290’s SIGINT/ELINT Common, High-band and Low-band Chassis. Switchblade provides the high dynamic range receiver needed for simultaneous reception of multiple direct and scatter paths for passive radar. Azure has also developed a wideband receiver module that covers the full range of legacy, modern, and emerging illuminators of opportunity. -Azure’s Bistatic Vector Cross Ambiguity Function (BVCAF) algorithm simultaneously suppresses strong direct path interference, detects weak bistatic target reflections, and estimates its range, Doppler, and bearing for target localization and characterization. This processing is done jointly and blindly eliminating the need for a known reference signal for direct path cancellation and weak target detection/localization. -Azure will leverage its advanced SIGINT/ELINT receiver hardware and processing capabilities to develop architectures for Navy long range passive radar surveillance architectures that leverage existing and future Navy SIGINT/ELINT assets and enable PBR using legacy, modern, and emerging IO.