Modeling of Sea Level Changes With GNSS-IR Method and Comparative Analysis With Tide Gauge Data

Abstract

The Global Navigation Satellite Systems Interferometric Reflectometry (GNSS-IR) method has emerged as a promising approach to analyzing reflected signals from various surfaces, providing valuable insights into the properties of reflection surfaces. By harnessing the capabilities of GNSS-IR, changes in sea level can be accurately determined when GNSS stations located in proximity to the sea possess a suitable viewing angle for receiving reflections from the sea surface. In this study, we conducted an extensive analysis of sea level changes using satellite data obtained from the MERS station, which is part of the Turkish National Permanent GNSS Network-Active (TUSAGA-Aktif) network, in the year 2021. Throughout the analysis process, we carefully considered the appropriate satellite elevation and azimuth angles, accounted for background conditions, applied dominant frequency limits, and employed minimum-maximum frequency filtering techniques. We evaluated the data using 16 distinct analysis strategies and verified the sea level measurements against the Erdemli Tide Gauge Station in the Turkish National Sea Level Monitoring System (TUDES). According to the strategies, the highest correlation was 0.94 and the lowest mean square error was 3.76 cm. The results showed that GNSS-IR is a powerful technique capable of determining sea level changes with high precision.