Patent ID: 7675813

Claim:
A method of taking measurements relating to a subterranean formation, comprising: generating acoustic waves; receiving at least one waveform including a component signal of interest portion; quality checking first arrival locations for the received waveform; determining the model order of an autoregressive model using Bayesian Information Criterion; determining a maximum likelihood function, based on the coefficients of the autoregressive model, within the signal of interest portion; determining a statistical function comprising the maximum likelihood function based on the coefficients of the autoregressive model; determining a point along the waveform using the statistical function; outputting a position of first arrival of the signal of interest, wherein the measurements taken are logging measurements relating to subterranean hydrocarbon reservoirs, wherein the quality checking comprises evaluating at least one of inconsistency of the received waveform having a clipped waveform, a signal-to-ratio of the received waveform and a spike in the received waveform before the determining a point along the waveform using the statistical function, wherein the evaluating comprises defining a reference waveform, using the reference waveform to compute a coherence ratio for each of the at least one waveform, and comparing the coherence ratio with a predetermined threshold to determine the inconsistency.