Miniature Ultra-Tightly Coupled Software-Defined Navigation (SDN) System

The hardware and software architecture for an ultra-tightly coupled (UTC) Software-Defined Navigation (SDN) system has been developed. Using a small single-aperture antenna the system will provide anti-jam (AJ) GPS capability and attitude measurements independent of an inertial navigation system (INS). The reconfigurable SDN architecture is structured to accept a variety of measurements from different sensors for optimum AJ GPS and ultra-tightly coupled GPS/INS performance. These include low-cost gyros and accelerometers, magnetic compass, magnetometer, altimeter, time-of-arrival (TOA), and electro-optical (EO)/infrared (IR) sensors. Furthermore, the direction-finding (DF) performance of the small antenna designed during the Phase I effort has been shown to be superior to any other system of its class by a factor of at least three. This small, conformal antenna makes it possible to obtain drift-free GPS-based attitude estimates that augment measurements obtained by low-cost gyros with large rate biases, thereby improving the overall system performance. For this Phase II effort Toyon proposes to further develop, build and demonstrate the small antenna and UTC SDN system in a realistic environment. To the extent permitted by the military, the SDN module will be developed as open-source software and will include the software GPS receiver, attitude estimation and anti-jam GPS algorithms, and the UTC GPS/INS navigation system.