Analysis and Prediction of Tidal Measurement Data from Temporary Stations using the Least Squares Method

Abstract

This research was conducted by equipping three temporary tidal stations located in three places inside Palu Bay with pressure-type tidal gauges. The stations recorded tidal series fluctuations for 4 months with a 5-minute sampling interval (Dt). Moreover, the simple and widely used least squares method (LSM) was applied to separate the harmonic constants of constituents, including amplitudes (Hi) and phases (gi), from the observed tidal series. A total of 11 dominant constituents were selected based on the largest magnitudes of tidal generating potential (CE), and these include M2, K1, S2, O1, P1, N2, Mf, K2, Mm, Q1, and Msf, which were diurnal, semidiurnal, and long-period constituents. The results showed that the semidiurnal constituents generated higher amplitudes than the diurnal constituents, while the long-period constituents produced quite small amplitudes. Furthermore, the ratios of amplitudes recorded showed that tidal in Palu Bay was mainly mixed with semidiurnal constituents. The difference between the observed and predicted values was quite small, and this showed the validity of the measurement conducted at the temporary tidal stations. The performance indicators applied also showed that LSM had acceptable accuracy compared to other methods. Moreover, tidal datums were calculated using the peak approach, and the average tidal range (RA) of Palu Bay was found to be 2.39 m. Doi: 10.28991/CEJ-2024-010-02-03 Full Text: PDF