PSN-L Email List Message

Subject: RE: Inverse filtering example
From: "Stephen Hammond" shammon1@.............
Date: Sun, 13 Mar 2011 13:32:28 -0700


Hi Bob, Did you happen to see this in the Larry's Redwood City PSN
datasets? If I remember correctly, Niles Canyon is local near Larry's
Redwood City location and is a USGS geophone up in the hills. The data
is impressive.  Regards, Steve Hammond PSN San Jose, Aptos CA.
 
110311.054624.cni.psn
  M8.9 7974km
from Niles Canyon, CA USA, NEAR THE EAST COAST OF HONSHU, JAPAN (GIF
 Image)

 

-----Original Message-----
From: psnlist-request@..............
[mailto:psnlist-request@............... On Behalf Of Bob McClure
Sent: Sunday, March 13, 2011 1:10 PM
To: psnlist@..............
Subject: Inverse filtering example


  I use inverse filtering to restore long-period response to my medium
period sensors. On major events, even geophones can be transformed into
long-period sensors.

  For example, I downloaded the following files:

110311.054500.sobe.psn
  Mw8.9
8750km from Sonderborg, Denmark, Near East Coast of Eastern Honshu,
Japan (GIF
 Image)
110311.054500.sobn.psn
  Mw8.9
8750km from Sonderborg, Denmark, Near East Coast of Eastern Honshu,
Japan (GIF
 Image)
110311.054500.sobz.psn
  Mw8.9
8750km from Sonderborg, Denmark, Near East Coast of Eastern Honshu,
Japan (GIF
 Image)

  I inverse filtered from the original period of 0.22 seconds to 20
seconds and posted the following volume file:

110311.055500.sobx.psn
  * M8.9
8750km from Sonderborg, Denmark [Inverse Filtered], Near East Coast of
Eastern Honshu, Japan (GIF
 Image)

which can be looked at or downloaded from
http://www.seismicnet.com/cgi-dos/event.exe

  If you integrate the data, you get peak displacements in the 3 to 4 mm
range, which seems about right.

  My inverse filter utility program, WQFilter.exe, can be downloaded
from http://sites.google.com/site/bobmcclure90

Bob





Message



Hi=20 Bob, Did you happen to see this in the Larry's Redwood City PSN = datasets? If I=20 remember correctly, Niles Canyon is local near Larry's Redwood=20 City location and is a USGS geophone up in the hills. The data is=20 impressive.  Regards, Steve Hammond PSN San Jose, Aptos=20 CA.
 
110311.05= 4624.cni.psn=20 M8.9 7974km from Niles Canyon, CA USA, NEAR THE EAST COAST OF HONSHU, = JAPAN (GIF=20 Image)
 
-----Original Message-----
From:=20 psnlist-request@.............. [mailto:psnlist-request@............... = On=20 Behalf Of Bob McClure
Sent: Sunday, March 13, 2011 1:10=20 PM
To: psnlist@..............
Subject: Inverse = filtering=20 example

  I use inverse filtering to restore=20 long-period response to my medium period sensors. On major events, = even=20 geophones can be transformed into long-period sensors.

  = For=20 example, I downloaded the following files:

110= 311.054500.sobe.psn=20 Mw8.9 8750km from Sonderborg, Denmark, Near East Coast of Eastern = Honshu,=20 Japan (GIF=20 Image)
110= 311.054500.sobn.psn=20 Mw8.9 8750km from Sonderborg, Denmark, Near East Coast of Eastern = Honshu,=20 Japan (GIF=20 Image)
110= 311.054500.sobz.psn=20 Mw8.9 8750km from Sonderborg, Denmark, Near East Coast of Eastern = Honshu,=20 Japan (GIF=20 Image)

  I inverse filtered from the original period = of 0.22=20 seconds to 20 seconds and posted the following volume file:

110= 311.055500.sobx.psn=20 * M8.9 8750km from Sonderborg, Denmark [Inverse Filtered], Near East = Coast of=20 Eastern Honshu, Japan (GIF=20 Image)

which can be looked at or downloaded from http://www.seismicne= t.com/cgi-dos/event.exe

 =20 If you integrate the data, you get peak displacements in the 3 to 4 mm = range,=20 which seems about right.

  My inverse filter utility = program,=20 WQFilter.exe, can be downloaded from http://sites.google.co= m/site/bobmcclure90

Bob

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