Using satellite receivers with a common clock in a small-sized GNSS compass

The paper presents the results from development and testing of a modified small-sized two-antenna GNSS compass containing two GNSS navigation receivers integrated with inertial measurement unit (IMU) on MEMS sensors. The compass has a short antenna baseline (less than the carrier wavelength). Specific feature of GNSS compass consists in arranging the IMU and antenna module on the same rotating platform, setting the time scale of GNSS receivers from the same clock, and using a comparatively accurate FOG to determine azimuth angle. The proposed GNSS compass uses an alternative heading determination algorithm by phase measurements with simultaneous observation of only one navigation satellite, providing 1 deg accuracy. Kinematic parameters of vehicle motion are received using both GPS and GLONASS satellites. In GNSS compass the difference phase measurements are generated at the level of first phase differences. Velocity, position, and phase difference measurements are processed using extended Kalman filter.