Heading and attitude determination system with low-cost IMU embedded inside one of multiple antennas

An integrated system for determining the position, velocity and 3D attitude of the vehicle is described. This system consists of the two-antenna GNSS receiver and a low-cost IMU embedded directly into one of the antennas. The GNSS component of this system allows to determine only two attitude angles of three Euler angles. These two angles are calculated from carrier phases of GNSS signals simultaneously received by both antennas in a common time scale. Inertial measurements are transmitted directly to the receiver from the IMU located inside one of antennas near its phase center. The RF cable is used to transfer these IMU data in conjunction with the GNSS signal received by this antenna. Measurements from the IMU are combined within the receiver with GNSS measurements of position, velocity and partial attitude. Operation principles of individual components of this integrated system are described. The results of experiments with this system, carried out on various types of vehicles and under various environment conditions are presented.