In a message dated 05/05/2009, tchannel@............ writes:

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.



Hi Ted, Bob,
 
    Can you simply highlight and then extract the  'good' part of the 
trace, minus the glitch?
 
    AmaSeis has a glitch removal filter that can be  selected. It has a 
'Median' filter in 'Control' which gets rid of  most spikes - this looks at the 
mean value and chucks out 'obviously'  incorrect readings. It also allows 
you to re-extract part of an extracted trace.  It has the usual HP and LP 
filters.
 
    Winquake seems to have only the LP and HP filters.  I don't know of any 
filters similar to the Glitch removal or Median filters in  AmaSeis. It 
would be useful to be able to re-extract part of an extracted  trace.
 
    Regards,
 
    Chris Chapman






In a message dated 05/05/2009, tchannel@............ writes:

  
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 noi=
se 
  spike at the beginning.
  
This noise was just someone walking aro=
und, or a 
  door opening etc.

Hi Ted, Bob,
 
    Can you simply highlight and then extract the=
 
'good' part of the trace, minus the glitch?
 
    AmaSeis has a glitch removal filter that can=
 be 
selected. It has a 'Median' filter in 'Control' which gets rid of 
most spikes - this looks at the mean value and chucks out 'obviously'=
 
incorrect readings. It also allows you to re-extract part of an extracted=
 trace. 
It has the usual HP and LP filters.
 
    Winquake seems to have only the LP and HP fil=
ters. 
I don't know of any filters similar to the Glitch removal or Median filter=
s in 
AmaSeis. It would be useful to be able to re-extract part of an extra=
cted 
trace.
 
    Regards,
 
    Chris Chapman