A carrier phase processor (CPP) for high dynamics carrier phase navigation

JDAM and similar DGPS based military applications impose tight error budgets on PPS receivers. Validation of these capabilities proves challenging with traditional ground-based and GPS-based reference systems. Available carrier-phase DGPS systems have great potential as reference systems, but their response to signal blockage and high dynamics is poor. Simple cascaded IMU formulations are inadequate under these very rigorous reception regimes, and therefore fundamental improvements in phase tracking robustness are needed. A new algorithm is proposed consisting of two stages: a) an integrated demodulation/navigation phase tracker, and b) a dual-frequency ambiguity resolution scheme optimized for P/Y service. The first stage employs optimal filtering of raw IQ correlator outputs at 1OOHz, using navigation domain covariances, IMU aiding, and carrier phase DGPS corrections. The Tracking and Imaging Systems signal simulator will be used to explore candidate algorithms in the high dynamics environment. Phase I activities include feasibility studies of aided and dual antenna versions of the carrier phase algorithms, and definition of modular interfaces between the carrier phase processor's CPU and the host GPS receiver's CPU. Efforts lead to early Phase II demonstration of the algorithms on NRaD's GPS simulator.