| 摘要 |
A method of performing a Vibroseis survey is described including the step of obtaining signals generated by activating vibratory sources at times To and T1, respectively, for a sweep period S and a listening time L such that T1 < To+S+L, wherein harmonic noise within the signals are attenuated using a first method to estimate the harmonics in a time-frequency interval in which harmonics of the sweep T1 overlap with the response to the fundamental of sweep T1 and using a second method for estimating the harmonics in a time-frequency with no overlap. In addition thereto, a method of attenuating the harmonic contamination of slip-sweep Vibroseis signals is described, using ground force signals or contamination-free signals and the Vibroseis signals to determine frequency dependent weights for at least a part of the frequency range of the Vibroseis sweep and using the frequency dependent weights to estimate the harmonics. The part of the frequency range referred to might be an overlap range in which the harmonics of a subsequent sweep overlap with a fundamental of an earlier sweep. |
