Anti-Jam Improvements by Combining Remotely Located Global Positioning System (GPS) Antennas on an Unpiloted/Uninhabited Aerial Vehicle (UAV) Platform

The Global Positioning System (GPS) is a vital element in numerous military and commercial applications. It is required that GPS receivers operate efficiently in hostile jamming environments. There is a critical need to incorporate advanced anti-jam techniques such as STAP and SFAP into UVA GPS receivers; however this normally requires the use of optimized multi-element CRPA antenna. The focus of this effort is to replace the multi-element CRPA with a number of fixed reception pattern antenna (FRPA) that will facilitate STAP/SFAP anti-jam techniques. For the phase I effort RBS Technologies and its subcontractor Raytheon Space and Airborne Systems plan to develop alternative architectures that combine several FRPA antennas into a pseudo-CRPA array together with the required subsystems and digital signal processing for incorporation of STAP/SFAP into a UAV GPS receiver. The antenna arrays are realized using existing FRPAs and alternative architectures will be considered for RF down conversion and STAP/SFAP processing. Anti-jam performance will be assessed using MATLAB/SIMULINK models and preliminary subsystem circuit simulations. The Phase I effort will result in identification of a viable approach for the use of the FRPA array antenna to implement anti-jam capability into UAV GPS receivers. BENEFIT: Extensive military applications are envisioned for a cost effective technique for using FRPA antennas to implement anti-jam UAV GPS receivers. These same techniques would apply to numerous airborne and ground platforms for both military and commercial applications.