Broadband Seismic Data with Vibrator Harmonic Signals

Traditionally, the harmonic signal generated by the vibrator is recognized as noise because it degrades the shot gather after correlating the raw shot record with the sweeping signal. In fact, from the blended acquisition point of view, the vibrator harmonic signal is also a signal like the sweeping one, which is of different sweep rates. Therefore, these harmonic signals can be used to broaden the bandwidth of the correlated shot gather and enhance their quality. We first separate the different orders of harmonic record from the raw shot record, and then use all these signals to correlate with their corresponding harmonic sweeping signal to extract different correlated components, and lastly stack them together to produce the final correlated shot gather which is of broader bandwidth and higher quality. The numerical examples on field data demonstrate the feasibility of our idea.