Integrating GPS/MEMS-based-IMU with single GPS baseline for improved heading performance

In a GPS/IMU integrated navigation system, problems are often encountered during periods of low-observability of heading considered essential in many applications such as antenna steering platforms, airborne navigation, swarm navigation, mobile mapping and harbor navigation. This paper proposes the use of a GPS/MEMS-based-IMU with a single GPS baseline measurement update in an EKF framework for an improved heading performance. The single GPS baseline update makes use of GPS-L1 only carrier-phase measurements from two antenna's mounted 1 m apart along the direction of motion of the platform. The epoch-to-epoch double-difference carrier-phase measurements formed is resolved for the integer ambiguity set and is incorporated directly in an EKF measurement update. The performance of the navigation system is demonstrated using data collected in an urban environment with sensors rigidly mounted on the rooftop of a van.