Radio Frequency (RF) Multipath Characterization & Transmitter Localization of Overwater Emitters

Localization of over water airborne contacts by a ship at sea or a land-based collector, typically requires either active sensing of the target or a combination of passive measurements from two or more cooperative platforms sharing information about either the time and frequency of arrival or angle of arrival of the RF energy from the aircraft. In both of those cases the friendly platforms are unable to maintain radio silence to successfully determine the location of the aircraft which compromises their position and intent. Expedition Technology, Inc. (EXP) is pleased to propose Sea-based Aircraft Intelligent Localization from Surface Scattering (SAILSS), a novel capability employing a single platform, Deep Learning based passive localization technique that utilizes the multipath propagation of RF emissions over a scattering surface. The SAILSS processing flow takes an observation made in a multi-element 2-dimensional array and forms a correlation matrix which is then passed to a neural network trained on Maximum Likelihood estimates from simulation to infer angles and ranges that produce the target location. The algorithm uses the angles, delays, knowledge of the propagation conditions, and the sea-state to determine the range to the target.