This paper describes and compares adaptive subtraction methods, with emphasis on multiple attenuation. Simple 1-D match-filter adaptive subtraction is compared to a pattern-matching subtraction method and to a 2-D filtering subtraction. The 1-D match-filter subtraction is inaccurate when different orders of multiples exist within one design window, since different orders of multiples have different relative amplitudes in commonly used surface-related multiple attenuation. Pattern-matching and 2-D filtering, which are independent of the relative amplitudes, are shown to attenuate the signal as well as the multiples.
Surface-related multiple attenuation (SRMA) has been shown to be an effective approach to removing multiples from seismic data that are difficult to attenuate using other methods. Surface-related multiple attenuation is generally done with two steps. The first step is calculating an estimate of the multiples. The second step is subtracting the estimated multiples from the recorded data.
