Synchrosqueezing transform for geoacoustic inversion with air-gun source in the East China Sea

This paper presents a geoacoustic inversion method combining with warping transform and synchrosqueezing transform to improve the precision of extracting modal dispersion curves in shallow water waveguide. Dispersive characteristic is often used to invert geoacoustic parameters, while the dispersion curves are hard to be extracted in short range. Warping transform can compensate the nonlinearity of received signal but the frequency resolution is still inaccurate. Synchrosqueezing transform sharpens the frequency resolution of warped modes, which makes the extracted dispersion curves more accurate. The comparison of simulation shows that the result using combined method is closer to the preset value when implementing geoacoustic inversion of dispersion characteristics. Furthermore, this method is used to invert the sea bottom parameters of a shallow water experiment in the East China Sea. The Bayesian method and insitu measurement are used to verify the reliability of inversion results.