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Annual Report 2000 - WIT

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267<br />

modifies the<br />

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, and the deconvolutional operator has a factor that scales the<br />

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”<br />

desired it is necessary that the<br />

lengths of the source-pulse and of the temporal window for truncation and smoothing<br />

do not contain the first multiple at distance . Consequently, the elongated operator<br />

ö-<br />

g<br />

The first term of the series is , where the variance<br />

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desired segment<br />

¢ïóï<br />

g<br />

ù<br />

ùg<br />

¢ïóï<br />

. From this we conclude that for windowing ¢ïóï<br />

with deconvolves the multiple of period , and the operator with length<br />

deconvolves ö- the multiples and , and so ö- on. (see Figure 2 and 3)<br />

ú ög<br />

ö- ö<br />

The application of the KBC solution in discrete form ù<br />

to a seismic trace, ,<br />

consists in a sequence of point-to-point operations organized in a definite sequence. ü<br />

g <br />

The matrix computed as:<br />

¹<br />

g<br />

g<br />

g<br />

g<br />

g<br />

(13)<br />

ý×ú<br />

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¹ 6<br />

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D©<br />

ú£º<br />

D©<br />

(14)<br />

g<br />

g<br />

g<br />

g<br />

g<br />

by:<br />

where ú<br />

g<br />

\©<br />

6 ý ¹ ®<br />

¹<br />

is the state transition matrix. The gain matrix ®<br />

g<br />

is calculated<br />

ß 6 - è (15)<br />

g<br />

g<br />

g<br />

¸ g<br />

The state vector is calculated by:<br />

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ø 6 ú£® ûÀ ø 6<br />

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And the output has the expression: + ü<br />

the multiple-free sismogram.<br />

g<br />

g<br />

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g <br />

S©<br />

ø 6<br />

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. The strategy is to recover<br />

We start identifying the variable with the non-stationary model.<br />

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The<br />

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seismic<br />

pulse is represented by the matrix:<br />

. The selection of the state vector<br />

is nonunique, and in this case the is defined as:<br />

$ ý þ<br />

š§ è (17)<br />

óÇü<br />

ü (16)<br />

g<br />

g<br />

g<br />

èBè è g<br />

The dynamic equations of the system to establish the recursive process of generation<br />

of the state vector is completed by the following model:<br />

ý ¤<br />

D©<br />

þ ú‚©<br />

(18)<br />

g<br />

g<br />

g<br />

g <br />

is theoretically considered as a white stochastic process.<br />

This equation<br />

projects the trace forward through a weighed sum of previous values in a<br />

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similar<br />

g þ<br />

formalism to the WHL. The coefficients are defined by a chosen model and experimentation,<br />

and in the present case has c#$ been the exponential model. The state is<br />

written as<br />

è (19)<br />

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