Analisis Tinggi Muka Air Laut Menggunakan Receiver Multi-Frekuensi dan Multi-GNSS di Perairan Sulawesi

Tide is a vertical variation of sea level. The tide of seawater is an essential component of a bathymetric survey. In general, tide observations are carried out by using tide poles at the survey site for bathymetry. As technology has developed, the use of the Global Navigation Satellite System (GNSS) has become increasingly possible in bathymetric surveys. Apart from determining the horizontal position, GNSS can also be used to determine the vertical position. One of the most accurate GNSS systems today is Japan's Quasi-Zenith Satellite System (QZSS). This system has satellites that are always orbiting in parts of Indonesia so that it will provide highly accurate satellite positioning services. In this study, observational data were obtained from multi-frequency and multi-GNSS receivers. The receiver can receive signals from the QZSS system. The observational data are then compared with the Geospatial Information Agency (BIG)'s tidal prediction model. Furthermore, an analysis was carried out to see the pattern error rate resulting from the two data. Error level test is done by calculating Root Mean Square Error (RMSE). This study's results indicate that the maximum and minimum RMSE values in the comparison of QZSS tidal observations and BIG tidal predictions are 2.317 m and 0.176 m, respectively, from a total of 11 observation days. The maximum RMSE occurred on 10 August 2019 and the minimum on 9 August 2019. Apart from 9 August 2019, good results were also obtained on 8, 12, 14, 15, and 16 August 2019 with an RMSE value of less than half a meter. Kata kunci : GNSS; pasang surut; prediksi pasang surut Geoid Vol. 16, No. 1, 2020, (68-79)