<s>
Semblance	B-General_Concept
analysis	I-General_Concept
is	O
a	O
process	O
used	O
in	O
the	O
refinement	O
and	O
study	O
of	O
seismic	O
data	O
.	O
</s>
<s>
The	O
new	O
data	O
received	O
following	O
the	O
semblance	B-General_Concept
analysis	I-General_Concept
is	O
usually	O
easier	O
to	O
interpret	O
when	O
trying	O
to	O
deduce	O
the	O
underground	O
structure	O
of	O
an	O
area	O
.	O
</s>
<s>
Weighted	B-Algorithm
semblance	I-Algorithm
can	O
be	O
used	O
for	O
increasing	O
the	O
resolution	O
of	O
traditional	O
semblance	O
or	O
make	O
traditional	O
semblance	O
capable	O
of	O
analyzing	O
more	O
complicated	O
seismic	O
data	O
.	O
</s>
<s>
Semblance	B-General_Concept
analysis	I-General_Concept
is	O
a	O
technique	O
that	O
first	O
began	O
to	O
be	O
developed	O
and	O
used	O
in	O
the	O
late	O
1960s	O
.	O
</s>
<s>
The	O
use	O
of	O
semblance	B-General_Concept
analysis	I-General_Concept
allows	O
for	O
the	O
removal	O
of	O
the	O
extra	O
noise	O
and	O
leaves	O
only	O
the	O
primary	O
reflection	O
.	O
</s>
<s>
Semblance	B-General_Concept
analysis	I-General_Concept
allows	O
for	O
the	O
refinement	O
of	O
seismic	O
data	O
.	O
</s>
<s>
This	O
is	O
done	O
by	O
developing	O
a	O
velocity	O
spectra	B-Algorithm
display	O
to	O
determine	O
the	O
velocity	O
through	O
different	O
layers	O
at	O
depth	O
.	O
</s>
<s>
With	O
this	O
information	O
it	O
becomes	O
fairly	O
easy	O
to	O
calculate	O
the	O
velocity	O
of	O
the	O
waves	O
as	O
they	O
travel	O
through	O
each	O
layer	O
by	O
using	O
the	O
equation	O
for	O
the	O
root	B-General_Concept
mean	I-General_Concept
square	I-General_Concept
velocity	O
starting	O
with	O
the	O
top	O
layer	O
and	O
working	O
downward	O
.	O
</s>
<s>
The	O
final	O
step	O
for	O
the	O
semblance	B-General_Concept
analysis	I-General_Concept
is	O
to	O
sum	O
all	O
of	O
the	O
data	O
that	O
has	O
been	O
corrected	O
for	O
velocity	O
.	O
</s>
<s>
This	O
is	O
done	O
with	O
the	O
use	O
of	O
a	O
computer	O
filter	B-Application
to	O
sum	O
together	O
all	O
of	O
the	O
events	O
that	O
the	O
traces	O
share	O
,	O
then	O
remove	O
the	O
ones	O
they	O
do	O
n't	O
.	O
</s>
<s>
The	O
result	O
is	O
a	O
single	O
data	B-General_Concept
set	I-General_Concept
that	O
has	O
all	O
of	O
the	O
primary	O
peaks	O
strongly	O
displayed	O
with	O
most	O
of	O
the	O
noise	O
removed	O
.	O
</s>
<s>
Semblance	B-General_Concept
analysis	I-General_Concept
will	O
not	O
work	O
properly	O
when	O
the	O
offset	O
from	O
the	O
shot	O
is	O
greater	O
than	O
the	O
depth	O
of	O
the	O
reflecting	O
layers	O
because	O
the	O
data	O
no	O
longer	O
has	O
a	O
hyperbolic	O
pattern	O
.	O
</s>
