PSN-L Email List Message

Subject: Off-scale Waveforms
From: "Timothy Carpenter" GeoDynamics@.......
Date: Tue, 4 Jan 2005 14:31:44 -0500


All,

=20

Please pardon me if this winds up a double posting =96 I'm still trying =
to get
e-mail addresses straightened out.

=20

In the normal course of my work I've occasionally run across the problem =
of
vibration sensors being pushed beyond their physical limits =96 i.e; the
suspended mass hits the end stops. For the most part, this has never =
been a
significant problem for me because there's always been another way to =
get
the data. However, when I downloaded seismic waveforms for the Dec 26th =
EQ
from Wooster, Ohio and Ann Arbor, Mi I found that their data had been
compromised. It appears that the seismometers hit their stops and badly
affected about 2-hours of the recordings. I believe this is the case at
several of the stations but certainly not all of them. I found many =
intact
waveforms on the PSN server.

=20

I've searched through my personal references as well as exercising =
Google;
but to no avail. So, I turn to the vast expertise of PSN. Are any of you
aware of a numerical process by which such signals can be reliably =
"fixed"?
I'm sure that a neural network could be trained to approximate the true
signal. But I'm more interested in a dynamic model consisting of a
mass-spring-dashpot model of the seismometer and a spring-dashpot model =
for
the stops at the end of travel.

=20

Regards,

-Tim-

=20

Timothy Carpenter, P.E., Pres.,
GeoDynamics Consultants, Inc.
5043 Whitlow Ct.
Commerce Twp., Mi 48382
248-363-4529 (voice & fax)
248-766-1629 (cell)
geodynamics@........... (primary)
geodynamics@....... (secondary)

=20

=20















All,

 

Please pardon me if this winds up a double posting = – I'm still trying to get e-mail addresses straightened out.

 

In the normal course of my work I've occasionally run = across the problem of vibration sensors being pushed beyond their physical = limits – i.e; the suspended mass hits the end stops. For the most part, = this has never been a significant problem for me because there's always been = another way to get the data. However, when I downloaded seismic waveforms for the = Dec 26th EQ from Wooster, Ohio and Ann = Arbor, Mi I found that their data had been compromised. It appears that the seismometers = hit their stops and badly affected about 2-hours of the recordings. I = believe this is the case at several of the stations but certainly not all of them. I = found many intact waveforms on the PSN server.

 

I've searched through my personal references as well = as exercising Google; but to no avail. So, I turn to the vast expertise of = PSN. Are any of you aware of a numerical process by which such signals can be reliably "fixed"? I'm sure that a neural network could be = trained to approximate the true signal. But I'm more interested in a dynamic model consisting of a mass-spring-dashpot model of the seismometer and a spring-dashpot model for the stops at the end of = travel.

 

Regards,

-Tim-

 

Timothy Carpenter, P.E., Pres.,
GeoDynamics Consultants, Inc.
5043 Whitlow Ct.
Commerce Twp., Mi 48382
248-363-4529 (voice & fax)
248-766-1629 (cell)
geodynamics@........... = (primary)
geodynamics@....... = (secondary)

 

 


[ Top ] [ Back ] [ Home Page ]