SBIR-STTR Award

The development of sophisticated anti-access/area denial (A2/AD) capabilities by our adversaries requires us to develop long range capabilities to mitigate this A2/AD threat. Extending the range of Over The Horizon Radars beyond their conventional single hop operating mode will potentially provide coverage out to 10000 km and beyond. We propose combining existing state-of-the art HF radar ray propagation, ionosphere, and surface terrain models with proven detector response matrix and data inversion techniques to accurately detect and calculate RCS for moving targets against the stationary background. The detector response matrix solution will characterize the effects of confusers and range ambiguity on radar performance using high fidelity physically rigorous simulations. The detector response matrix solution has been applied successfully in gamma-ray astrophysics for decades. What is new and unique here is combining the detector response matrix technique from astrophysics with state of the art radar environment modeling simulations to develop the HF-OTHR multi-hop capability. This approach provides detection, tracking, and discrimination capability for HF-OTHR systems out to ranges that will provide sensor coverage to support mitigation strategies for the A2/AD threat.

Extending the range of High Frequency (3MHz-30MHz) Over The Horizon Radars (HF-OTHR) to multi-hop range will provide a significant capability enhancement to neutralize anti-access/area denial (A2/AD) capabilities developed by US adversaries. To provide target detection for OTHR at multi-hop ranges we will develop the Radar Environment Response Function (RERF) solution that employs a comprehensive processing system of ionospheric propagation characterization to determine target matched filters. \n\n The RERF solution compares OTHR clutter returns to an ensemble generated using a comprehensive set of ionospheric states to select the one that most closely matches the current conditions. Once the ionospheric state is selected, then matched filter responses can be generated for potential targets as a function of target position, velocity and Radar Cross Section. These matched filters can be applied to Doppler processed data to optimize the target detection process, particularly at multi-hop ranges. The RERF solution combines existing state-of-the art HF radar ray propagation, ionosphere, and surface terrain models with proven detector response matrix and data inversion techniques that have been applied successfully in gamma-ray astrophysics for decades. In order to demonstrate the practicality of implementing the RERF algorithm, we will we will stand up a side car supporting the RERF algorithm and databases connected to an operational OTHR data processing string. This will allow us to demonstrate the RERF algorithm with actual radar data in real time.