METHOD FOR DETERMINING BEST LOW-FREQUENCY SCANNING SIGNAL OF CONTROLLED SEISMIC SOURCE

摘要

The present invention is a method for determining a best low-frequency scanning signal of a controlled seismic source. The method comprises: using equifrequency scanning signals, gradually increasing the output force of a seismic source to perform excitation, fitting the actually output maximum output force of actually measured low-frequency sampling points of the seismic source using the least square method, determining a low-frequency output curve of the controlled seismic source according to the focuses of a maximum fitted weight dropper displacement curve and a system flow curve, calculating the scanning duration of a low frequency range, and the frequency, the amplitude and the phase of each sampling point of the low frequency range, generating a scanning signal and practically testing same on the seismic source, and obtaining a best low-frequency scanning signal until the vibration results don't exceed the weight dropper displacement limit or the flow limit. The present invention enables low-frequency components of a scanning signal of a controlled seismic source to be apparently strengthened, is applicable to the existing controlled seismic source, and can exert the maximum potential of the low frequency of the controlled seismic source. The distortion of a low-frequency signal is small, and the output spectrum of the controlled seismic source is smoothly whitened, thereby being able to better protect the controlled seismic source.