Existing sequential parameter estimation methods use the acoustic pressure of a line array as observations.The modal dispersion curves are employed to estimate the sound speed profile (SSP) and geoacoustic parameters based on the ensemble Kalman filter.The warping transform is implemented to the signals received by a single hydrophone to obtain the dispersion curves.The experimental data are collected at a range-independent shallow water site in the South China Sea.The results indicate that the SSPs are well estimated and the geoacoustic parameters are also well determined.Comparisons of the observed and estimated modal dispersion curves show good agreement.