Comparative Performance of Real-Time GNSS Positioning Solutions for Marine Applications Under Different Correction Strategies

Accurate and reliable positioning is a fundamental requirement for marine applications, particularly in hydrographic surveying, where real-time data acquisition is essential. Despite recent advances in Global Navigation Satellite System (GNSS) technologies, the comparative performance of different real-time correction strategies under marine conditions remains insufficiently addressed. This study presents a comparative performance analysis of three real-time GNSS positioning solutions—Precise Point Positioning–Real-Time Kinematic (PPP-RTK), Network RTK (NRTK), and Single-Baseline RTK (SBL-RTK) with Post-Processed Kinematic (PPK) coordinates adopted as the reference. Performance was assessed using statistical accuracy metrics in accordance with the International Hydrographic Organization (IHO) S-44 standards. At the 95% confidence level, the Total Horizontal Uncertainty (THU) values were 5.6 cm for PPP-RTK and 4.5 cm for NRTK, while the Total Vertical Uncertainty (TVU) values were 3.6 cm and 6.8 cm, respectively. Both NRTK and PPP-RTK solutions met IHO S-44 standards. Under the test conditions considered in this study, the SBL-RTK solution exhibited lower performance than the other solutions, mainly due to the higher proportion of float and stand-alone solution epochs. The findings indicate that the NRTK solution is suitable for near-shore hydrographic surveys where cellular connectivity is available. PPP-RTK represents a reliable alternative for marine applications through satellite-based correction services. This study contributes to the evaluation and selection of appropriate GNSS-based positioning strategies for hydrographic surveying.