A Miniature Ultra-Tightly Coupled Software-Defined Navigation (SDN) System with Direction-Finding, Attitude-Determination and Anti-Jam GPS

Toyon Research Corporation proposes to develop a miniature ultra-tightly coupled software-defined navigation (SDN) system that can provide anti-jam (AJ) GPS capability and attitude measurements independent of an inertial measurement unit (IMU). Using a single-aperture 4-cm antenna, the system will provide angle-of-arrival (AoA) measurements for GPS jammers as well as signals outside the GPS band. These AoA measurements can assist emitter localization algorithms that use time-difference-of-arrival (TDOA) and frequency-difference-of-arrival (FDOA) methods, and can be used for threat identification and elimination. The SDN system will also accept a variety of IMU measurements for optimum AJ GPS and ultra-tightly coupled GPS/inertial navigation system (INS) performance. These may include low-cost micro-electro-mechanical systems (MEMS), magnetic compass, magnetometer, altimeter, time-of-arrival (TOA) inputs, and electro-optical (EO)/infrared (IR) sensors. The drift-free GPS-based attitude estimates will augment measurements obtained by low-cost MEMS gyros with large rate biases, thereby improving the overall system performance. Moreover, Toyon has teamed with Analytical Graphics, Inc. (AGI), the developer of the industry standard Navigation Tool Kit (NTK) and Satellite Tool Kit (STK) software to analyze and verify the accuracy of the SDN system and sensor mixture specifically for TDOA and FDOA precision geolocation applications. Furthermore, the SDN module will be developed as open-source software.