A new autoregressive moving average modeling of H/V spectral ratios to estimate the ground resonance frequency

Abstract

We propose a new method to estimate the horizontal-to-vertical (H/V) spectral ratio using microtremor measurements. The technique is based on modeling the H/V transfer function by means of an AutoRegressive Moving Average (ARMA) filter. As compared with the conventional, Fourier-based spectra processing routines, this method is efficient in extracting the fundamental resonant frequency with a higher spectral resolution. We demonstrate its usefulness by an application to several sites in northeastern Iberian Peninsula. For the data sets examined, our approach shows improvement over the Fourier transform-based method under adverse experimental conditions. We conclude that the new technique provides robust estimates of the fundamental resonance frequency and can be effective to characterize empirically the unconsolidated sediment thickness and bedrock geometry.