2024 Volume 70 Pages 1-12
In the Global Navigation Satellite System （GNSS） positioning on the ship，a GNSS antenna fixed on the ship receives radio waves from GNSS satellites, and the position of the antenna is estimated. Although the antenna is fixed on the ship, the ship itself is propelled, and due to changes in sea level, the shipʼs hull violently oscillates vertically and horizontally （pitch, roll, and heave）. There have been few studies that have experimentally and quantitatively investigated the effects of ship body motion on GNSS ranging. We conducted the experiments utilizing a cart mounted on a GNSS antenna subjected to 21 distinct motion patterns, to effectively capture the response of GNSS measurements to controlled ship-like movements. Equipment utilized comprised the GNSS antenna and NetR9 base station receiver made by Trimble Inc., capturing signals from the GPS, GLONASS, and Galileo on various frequencies including L1, L2, and L5. The experiments were conducted atop buildings at the Institute of Industrial Science of the University of Tokyo, with the cart movements restricted along the one-dimensional axis and the antenna pivoting within the plane perpendicular to the direction of the cart movement. Obtained GNSS data were initially recorded in Trimbleʼs proprietary T02 format and subsequently converted to the Receiver Independent Exchange Format （RINEX） version 2.11 using Trimbleʼs RINEX converter. We introduced some results of the positioning analysis under various conditions, performed by the kinematic precise point positioning using the open source software for GNSS positioning （RTKLIB）.
