Annual Report 2000 - WIT

7
7
searches ¡ HNJOL for ¢IHNJML £ and
7
7
12
¢IHNJOL £§¦©¨ Unfortunately, can be determined neither in the CMP stacked section nor
in the original CMP gathers. According to the stacking operator ¢IHKJML £3¦©¨ (1), has no
£3¦6¨ corresponding to each conflicting dip ¡ HKJML becomes necessary.
¢IHKJML
influence in the ZO section , and in the CMP gather , ¢IHNJML £§¦©¨ and
PQRBC 1ST*
cannot be separated. To solve this problem, we propose to perform the additional
HKJML ¡
search ¢IHKJML £3¦6¨ for in another subset of the multi-coverage data, namely in the commonshot/common-receiver
(CS/CR) gather. This gather is defined by the condition U
WB
UX?YU
U . A simplified flowchart of this strategy is depicted in the following flowchart:
V'
multi-coverage data
automatic CMP stack
ZO section
HNJML and ¢ HKJML £ ¡
search ¢ HKJML £§¦©¨ for in CS/CR gather
HNJOL , ¢ HKJML £§¦©¨ , and ¢¥£ HKJML
¡
optional optimization and stack with multi-coverage data
The Z index denotes the different events detected for one and the same ZO sample. If
only one event for a particular ZO sample is detected, we can still use the pragmatic
scheme without the explicit search ¢IHKJML £3¦6¨ for . Otherwise, the automatic CMP stack
can be easily
£
detected, whereas the stacking velocity is not explicitly used anymore.
only serves to provide a simulated ZO section in which ¡ HNJML and ¢ HKJML
The additional one-parametric search ¢IHKJML £3¦©¨ for is almost identical as the already
implemented search ¢IHNJOL £ for . Thus, a new algorithm to perform this search is not
required.
The determination of the emergence angles is based on an approximation of the
CRS operator (1) ¢¥£ for in the ZO section . This implies that
1_`*
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