1. A method for automatically characterizing an echo contained in an ultrasonic signal, the ultrasonic signal being generated with an ultrasonic transducer, the method comprising: a. receiving data corresponding to the ultrasonic signal with the ultrasonic transducer; b. calculating an energy ratio of the ultrasonic signal and localizing the echo contained in the ultrasonic signal using the energy ratio; c. windowing a portion of the ultrasonic signal around the localized echo; d. calculating a Fast Fourier Transform (FFT) and a Hilbert envelop of the windowed portion of the ultrasonic signal; e. estimating M echo parameter vectors from the FFT and the Hilbert envelope of the windowed portion of the ultrasonic signal, wherein each of the M echo parameter vectors comprises a plurality of echo parameters; f. calculating M parametric echo models based on each of the M echo parameter vectors; and g. iteratively minimizing a difference between the windowed portion of the ultrasonic signal and a sum of the M parametric echo models.