Experimental Assessment of Course over Ground and Heading Determination for Marine Vessels Using Single- and Dual-Antenna GNSS Positioning Solutions

This study aims to determine the course over ground (COG) and heading angle of a marine vessel for hydrographic surveying and navigation using single- and dual-antenna GNSS configurations. Three aspects were investigated. (1) The vessel COG was determined from coordinate differences between epochs using a single-antenna GNSS solution. Network RTK (NRTK) and Precise Point Positioning with Ambiguity Resolution (PPP-AR) were evaluated, while Post-Processing Kinematic (PPK) was used as the reference solution. When the vessel started moving, COG estimates became considerably more stable, with RMSE values of 0.9233° for NRTK and 2.0727° for PPP-AR. (2) Dual-antenna GNSS solutions were used to determine vessel heading. For all epochs, the heading differences between the PPP-AR and PPK solutions yielded RMSE values of 0.2475° and 0.4068° for the 4.00 m longitudinal and 2.07 m transverse baselines, respectively. (3) Baseline configuration effects were also investigated. Although the shorter transverse baseline provided lower heading RMSE during the stationary period, additional analyses indicated that this counter-trend was primarily associated with systematic angular offsets rather than greater angular dispersion. Normalized baseline-length errors were smaller for the longitudinal configuration. These results demonstrate the combined influence of baseline length, orientation, and observation conditions on GNSS-based marine vessel heading determination.