Method for estimating and removing artifact noise from seismic data

A method for estimating noise in a seismic signal, comprising the steps of:

• representing the seismic signal as a combination of a geologic signal and a noise signal;
• separating the seismic signal into a plurality of frequency bands;
• and
• for each band,
• decomposing the representation of the seismic signal into a linear combination of orthonormal components;
• identifying one or more of the orthonormal components in which the geologic signal and the noise signal are substantially uncorrelated;
• expanding the noise signal as a product of an unknown amplitude modulation signal and a known spatial periodicity signal at the identified components;
• estimating the amplitude modulation signal at the identified components;
• and
• multiplying the estimated amplitude modulation signal by the spatial periodicity signal to generate an estimated noise signal for the band, and
• adding the estimated noise signals from each of the frequency bands to generate a total estimated noise signal.

A method for estimating noise in a seismic signal, wherein the seismic signal comprises a three-dimensional volume, comprising the steps of:

• representing the seismic signal as a combination of a geologic signal and a noise signal;
• separating the seismic signal into a plurality of vertical intervals;
• and
• for each interval,
• decomposing the representation of the seismic signal into a linear combination of orthonormal components;
• identifying one or more of the orthonormal components in which the geologic signal and the noise signal are substantially uncorrelated;
• expanding the noise signal as a product of an unknown amplitude modulation signal and a known spatial periodicity signal at the identified components;
• estimating the amplitude modulation signal at the identified components;
• and
• multiplying the estimated amplitude modulation signal by the spatial periodicity signal to generate an estimated noise signal for the interval.