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Soner Bekleric Title of Thesis: Nonlinear Prediction via Volterra Ser

Soner Bekleric Title of Thesis: Nonlinear Prediction via Volterra Ser

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4.1. LINEAR PREDICTION IN THE F − X DOMAIN 48<br />

An ARMA model can be approximated by a long autoregressive model (AR), which<br />

turns out to be a representation <strong>of</strong> the linear prediction problem. In summary, linear<br />

events in t−x space transform into complex sinusoids in the f −x domain and linear<br />

prediction filtering can properly model the spatial variability <strong>of</strong> the waveforms at<br />

any given monochromatic temporal frequency f.<br />

The seismic signal is considered to be an AR model; let us assume a single<br />

waveform in time domain. In addition, let’s assume that the signal has linear<br />

moveout<br />

s(x, t) = a(t − xθ) (4.1)<br />

where x is <strong>of</strong>fset <strong>of</strong> the trace, t is the time and θ is the slowness <strong>of</strong> the event. In<br />

the frequency domain this signal becomes<br />

S(x, f) = A(f)e −i2πfθx<br />

(4.2)<br />

where A(f) denotes the source spectrum and f is the temporal frequency for x. By<br />

discretizing x = (j − 1)δx, f = fl<br />

Sjl = Ale −i2πflθ(j−1)δx<br />

(4.3)<br />

I can develop this model as a function <strong>of</strong> wave number by fixing kl = 2πflθ equation<br />

(4.3) becomes<br />

Sjl = Ale −ikl(j−1)δx<br />

(4.4)<br />

I can define the problem by predicting data along the each trace to fix temporal

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