Patent ID: 7420877

Claim:
A method for processing an echo profile, comprising: providing a pulse-echo ranging system; providing a time-varying threshold function; comparing the echo profile with the threshold function; identifying valid echoes in those portions of the echo profile which exceed timely corresponding portions of the threshold function; determining confidence levels based on differences between the portions of the echo profile and the timely corresponding portions of the threshold function; assigning the confidence levels to the identified echoes; selecting the echo with the highest confidence level as the echo of interest; determining whether the portion of the threshold function which timely corresponds to the selected echo of interest is part of a hump-shaped section of the threshold function; reshaping the section to a reduced hump amplitude; and redetermining the confidence level of the echo of interest based on differences between the profile of the selected echo of interest and the timely corresponding portion of the reshaped threshold function exceeded by the selected echo of interest.