GNSS Based Attitude Determination
Dr Boris Vassilev, Dr Boriana Vassileva
The proposed GNSS Based Attitude Determination (GBAD) technique exploits velocity information acquired by GNSS receivers. For this purpose, velocities are measured by one or two receiver antennas shuttled within the body coordinate system. If the components of vectors are known in two coordinate systems, the attitude between these coordinate systems can be determined. GBAD uses velocity vector information in the body coordinate system (a priori known) and the geographic coordinate system (provided by the GNSS receiver). Pitch, roll, and heading are determined after the extraction of velocity components of the antenna in geographic coordinate system from the measured sum of body velocity and antenna velocity components in geographic coordinate system. This GBAD technique can be implemented within a GNSS receiver and offers a number of advantages, such as high accuracy, a small size, reliability, and compatibility with unmanned aerial vehicles, airplanes, ships, and cars. The antenna motion within the body frame is also known, which makes it possible to filter velocity errors, improve the system’s performance, and monitor its integrity.