## PSN-L Email List Message

Subject: Re: WinQuake Filtering Advice and/or Tutorial
From: "Jerry Payton" gpayton880@.......
Date: Fri, 21 Jul 2006 16:52:52 -0500

```Hey Thanks Bob,

You may cause my brain cells hurt, but what the heck.  You know, medical
doctors say that the human brain has no nerve endings to hurt, BUT my head
sure hurts trying to think sometimes!

I'll check these out.
Jerry
----- Original Message -----
From: Bobhelenmcclure@.......
To: psn-l@..............
Sent: Friday, July 21, 2006 4:46 PM
Subject: Re: WinQuake Filtering Advice and/or Tutorial

Hi Jerry,

I design and code my own seismic digital filters, and I have yet to find
any reference that follows the "KISS" principle. The subject is highly
mathematical. I got the most help on Butterworth filter design from

http://kwon3d.com/theory/filtering/lpass.html

The information there is drawn from the bible of signal processing:

Oppenheim, A.V., & Schafer, R.W. (1989). Discrete-time signal processing.
Englewood Cliffs, NJ: Prentice Hall.

You will find my program "WQFilter" for filtering WinQuake files in the
file "seismic_dataq.zip" at
http://www.jclahr.com/science/psn/mcclure/index.html

To explore the impulse response and bandpass properties of any filter in
WinQuake or WQFilter, use "Impulse.psn" as the source file. After filtering
it, you will see the impulse response of the filter. Use WinQuake's FFT to
reveal the corresponding spectral response of the filter. This is a very
useful exercise, even if you decide not to dig deeper.

Bob McClure

Hey Thanks =
Bob,

You may cause my brain =
cells hurt,=20
but what the heck.  You know, medical doctors say that the human =
brain has=20
no nerve endings to hurt, BUT my head sure hurts trying to think=20
sometimes!

I'll check these =
out.
Jerry

----- Original Message -----
From:=20
Bobhelenmcclure@....... =

To: psn-l@..............
Sent: Friday, July 21, 2006 =
4:46 PM
Subject: Re: WinQuake Filtering =
and/or Tutorial

Hi Jerry,

I design and code my own seismic digital filters, and I =
have yet=20
to find any reference that follows the "KISS" principle. The subject =
is highly=20
mathematical. I got the most help on Butterworth filter design from =

http://kwon3d.com/=
theory/filtering/lpass.html

The information there is drawn from the bible of signal=20
processing:

Oppenheim, A.V., & Schafer, R.W. (1989). Discrete-time signal =

processing. Englewood Cliffs, NJ: Prentice Hall.

You will find my program "WQFilter" for filtering =
WinQuake=20
files in the file "seismic_dataq.zip" at http://www.=
jclahr.com/science/psn/mcclure/index.html

To explore the impulse response and bandpass properties of =
any=20
filter in WinQuake or WQFilter, use "Impulse.psn" as the source file. =
After=20
filtering it, you will see the impulse response of the filter. Use =
WinQuake's=20
FFT to reveal the corresponding spectral response of the filter. This =
is a=20
very useful exercise, even if you decide not to dig deeper.

Bob McClure
```