An Array of Digital Antenna Elements for Mitigation of Multipath for Carrier Landings

NAVSYS has developed a new Digital Antenna Element design for integration with a Controlled Reception Pattern Antenna (CRPA) which offers significant advantages over conventional Digital Antenna Electronics for high integrity GPS applications such as the Joint Precision Approach and Landing System (JPALS). Instead of performing spatial processing within the Digital Antenna Electronics, the Digital Antenna Elements each output the raw sampled digital data from each of the CRPA antenna elements. This allows the GPS receiver to perform embedded spatial integrity monitoring and optimize the spatial processing for each internal receiver channel to maximize the signal/jamming ration (S/J) or to minimize the signal/multipath levels (S/M). This paper describes the Digital Antenna Element and Receiver design and includes test results collected onboard the USS Truman to evaluate the improvements possible using digital beam forming for multipath mitigation in this environment.