BAND PASS/BLOCK

Band pass/blocking is basically the construction of
a band pass or reject filter where wavelet coefficients are
modified over a scale bandpass. For example, in the above
figure showing the Bandpass Blocking box of the GUI, a scale band
is chosen between 1 and 1000 seconds. In addition, a
threshold of 0% is chosen. The CWT coefficients in this band
will be multiplied by 0. If 5% had been chosen, then the
coefficients would be multiplied by 0.05. After
multiplication, the inverse CWT is computed to display the
filtered seismogram.
Here is the result using the canonical seismogram:

Here is an example for band pass filtering with the CWT. A
scale range of 0.3 to 1s is chosen for the band pass.

giving the result

Note that the scale unit is seconds. The CWT Scalogram is
plotted in log10(scale) vs time. In experimenting with
Bandpass Blocking it is helpful to use the MatLab datatip

to choose scale points on the Scalogram. The numerical values
will be in log10. The Scale Numeric Calculator at the bottom
of the GUI

is provided to covert these log10 data values to actual values that
can be input in the Bandpass Blocking edit boxes.
To use the calculator, input a value in a box and press the keyboard
<return> key. The conversion goes both ways.
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