Analysis of Global Tidal Model Application for Hydrographic Separation Model Development

Hydrography is a science that focuses on the measurement and description of the characteristics of the sea and coastal areas, with tides as an important element in determining vertical references. In the deep sea, the limited distribution of tide stations makes it difficult to accurately determine Chart Datum. Global Navigation Satellite System (GNSS) technology allows direct, high-Accuracy reduction of bathymetry data to a specific reference system such as an ellipsoid (WGS84). Hydrographic survey without directly measuring tides is one of the main benefits of applying hydrography separation model (HSM). This study aims to explore the application of global tidal model in the development of Hydrography Separation Model (HSM) in Southern Java Waters. The TPXO10-Atlas v2 and FES2014 models were used to determine the Lowest Astronomical Tide (LAT) value as the Chart Datum reference. Evaluation of ten BIG tidal stations showed that the TPXO10-Atlas v2 model has a Root Mean Square Error (RMSE) value of 0.079 meters, while the FES2014 model is 0.081 meters. Based on these results, the TPXO10-Atlas v2 was selected as the best model for HSM development. HSM implementation was carried out by integrating GNSS data, bathymetry, INAGEOID2020 v2.0 undulation model, and DTU21MSS mean sea level model. A depth difference of 13 meters was obtained against the LAT reference.