GPS Anti-Jam Receiver (AJR)


The Anti-jam GPS Receiver (AGR) designed by Raytheon supports the Tactical Tomahawk missile program. The system uses PPS (Y-code) GPS signals, operating on both the L1 and L2 frequencies. When configured with a multi-element Controlled Reception Pattern Antenna (CRPA), the AGR’s post-correlation nulling techniques allow continued satellite track in the presence of high levels of hostile jamming. This patented anti-jam concept also provides satellite beam steering, to further enhance the tracking thresholds, and to mitigate the “spurious nulls” that can degrade the performance of other nulling implementations (e.g., pre-correlation). The AGR sequentially tracks up to eight visible satellites, and provides high-quality pseudorange/delta pseudorange (PR/DPR) measurements corrected for the effects of selective availability. The Tactical Tomahawk’s navigation processor then uses the PR/DR measurements to yield a high-performance navigation solution.