Assessment of Low-Cost Tide Gauges to Meet GLOSS 1-cm Precision and Accuracy Standards: A Case Study on Pramuka Island, Indonesia

Zulfikar Adlan Nadzir (Department of Geomatic Engineering, Institut Teknologi Sumatera, Jl. Terusan Ryacudu Way Hui, Jati Agung District, South Lampung 35365, Indonesia. Institute of Geodesy and Geoinformation, University of Bonn, Nussallee 17, Bonn 53115)
Irdam Adil (Department of Geomatic Engineering, Institut Teknologi Sumatera, Jl. Terusan Ryacudu Way Hui, Jati Agung District, South Lampung 35365)

Forum Geografi
Vol. 38 No. 2 (2024): August 2024

The expansion of the tide gauge network along the coasts is essential for better monitoring of sea-level dynamics. Owing to climate change, the urgency has been exacerbated, especially during the last two decades. However, densification a challenging task because of the lack of affordability of the sensor, especially in the Global South. Further, the precision and accuracy requirements of 1-cm imposed by the Global Sea Level Observing System (GLOSS) is too restrictive, particularly for low-cost tide gauge sensors. Here, we evaluated the performance of a low-cost DIY tide gauge in meeting these standards. Three sets of sea level observations from IR-TIDES, a DIY tide gauge sensor observed in 2016 and 2018, were subjected to a performance test in terms of precision and accuracy in comparison with a global tide model and two neighbouring established tide gauges. All three datasets were estimated to have an 8- cm standard deviation as a metric for the precision level. In terms of accuracy, the IR-TIDES datasets had a standard deviation of 25 cm and a correlation coefficient of 0.616. Overall, IR-TIDES demonstrated sufficient precision while still lacking accuracy, partially meeting the GLOSS quality standard. These findings could strengthen the confidence level of a low-cost DIY tide gauge, especially for use as a back-up and redundant sensor for an established tide gauge station after ad-dressing the limitations.