Analyzing the tidal frequency content using Karhunen-Loeve Expansion technique

Abstract

The Karhunen-Loeve Expansion (KLE) technique has been recently applied by geophysicists for analyzing the temporal variations of dynamic systems such as the ocean-atmosphere interface, crustal deformation and fault systems. The application of this method to tidal data can provide a direct insight into the efficiency and reliability of this method in reconstructing a periodic signal. The comparison of the obtained results to those proposed by the least squares harmonic estimation (LSHE) as a newly developed method which is widely used in geodetic community for analyzing the GPS time series can be of significant interest for both geodesists and geophysicists. This paper applies the KLE method to the tidal time series of the Workington station in United Kingdom and compares the given results to those suggested by the LSHE method. The detection of the majority of the expected long period constituents and the larger number of the detected low frequency components by KLE as compared to the least squares harmonic estimation emphasizes on the efficiency and the predominance of this method to the LSHE technique

Keywords

• karhunen-loeve expansion technique
• spectral analysis
• tidal constituents