Code/carrier Phase Compensation (CPC) for GPS Anti-Jam Receivers on Rotary Wing Aircraft Platforms

Beamforming/null steering algorithms have been developed for antenna installations on ships and fixed wing aircraft where navigational accuracy is achieved at the expense of greater complexity and cost in the antenna electronics. A rotary wing aircraft presents a more challenging radio frequency (RF) environment than ships and fixed wing aircraft where both the rotor blade modulation and reflection may affect anti-jam and GPS receiver performance. The objective of this SBIR program is to develop advanced adaptive weighting algorithms to mitigate potential code and carrier phase bias errors introduced by Controlled Reception Pattern Antenna (CRPA) nulling algorithms and maintain or improve navigation accuracy in the presence of rotor blade jammer reflection and modulation of GPS satellite signals. Mayflower proposes to leverage its Small Antenna System (SAS) technology developed for rotary wing platforms with innovative advanced adaptive weighting algorithms that mitigate antenna induced phase biases in GPS code and carrier phase measurements in the rotary wing environment. In Phase I of this SBIR, Mayflower will prove the feasibility of an advanced adaptive weighting algorithm through simulation and analysis. In Phase II, our plan will implement an enhanced AJ solution to demonstrate the ability to mitigate GPS carrier phase and pseudo-range biases induced by jamming in a rotor-blade environment. Under Phase III, Mayflower will develop form-fit AJ electronics for transitioning the technology to current and future rotary wing naval platforms such as the Navy"s H-60 aircraft.