Ted -

As you said it is a noise spike.  In that case you might be able to  
filter it out with selective flittering such as a notch or bandpass  
filter.  Larry has placed multiple filtering options in WinQuake.  I  
have had some limited success in removing spikes.  The problem is how  
much filtering to apply.  This is a trail and error process and  
depends upon the event and distance.  Closer events have generally  
higher frequencies than teleseismic event.  Again, a process of trail  
and error at best.

Maybe someone has a process that works, but I am unaware of any method  
other than filtering out the frequency of the spike and hopefully not  
distorting the rest of the seismogram.

Bob Hancock


On May 5, 2009, at 10:26 AM, tchannel wrote:

> Hi Folks,   I have a question about a .psn file or .sac.   Is there  
> anyway to edit an unwanted spike from a data file.   I had a .psn  
> the other day, that looked very nice except for a large noise spike  
> at the beginning.
> This noise was just someone walking around, or a door opening etc.
>
> It would have nice to be able to edit that out and save the change.  
> I know you can filter these out to some degree, but is there a way  
> to cut them out like one would do with a .wav file, using a sound  
> file editor?
>
>
> Thanks, Ted

Ted =
-

As you said it is a noise spike.  In =
that case you might be able to filter it out with =
selective flittering such as a notch or bandpass filter. =
 Larry has placed multiple filtering options in WinQuake.  I =
have had some limited success in removing spikes.  The problem is =
how much filtering to apply.  This is a trail and error process and =
depends upon the event and distance.  Closer events have generally =
higher frequencies than teleseismic event.  Again, a process of =
trail and error at =
best.

Maybe someone has a process =
that works, but I am unaware of any method other than filtering out the =
frequency of the spike and hopefully not distorting the rest =
of the seismogram.

Bob =
Hancock


On May 5, 2009, at 10:26 AM, =
tchannel wrote:

Hi Folks,   I have a question about =
a .psn file or .sac.   Is there anyway to edit an unwanted =
spike from a data file.   I had a .psn the other day, that =
looked very nice except for a large noise spike at the =
beginning.
This noise =
was just someone walking around, or a door opening =
etc.
 
It =
would have nice to be able to edit that out and save the change. I know =
you can filter these out to some degree, but is there a way to cut them =
out like one would do with a .wav file, using a sound file =
editor?
 
 
Thanks, =
Ted

=