PSN-L Email List Message

Subject: Re: Metods for Improving SNR for events ??
From: "Geoffrey" gmvoeth@...........
Date: Sun, 17 Sep 2006 23:53:36 -0700


Mr. Jerry Payton;

First:
I would say try to limit your bandwidth
as well make your system flat between
4 seconds and 9 Hz if possible.

Damping small as possible but an absolute necessity.

Increase your system gain until noise
is apparent in the charts.

Limiting your bandwidth to the range of
P waves only instead of everything.

The USGS seems to want only first times of arrivals
and they are looking for the station which
registers closest to the event in question.

Second would be to find an isolated piece
of ground and bury your geophone underground
about 18 inches or so and away (several feet)
from any structures. But a proper chamber is in order
to avoid moisture contamination.

Third is to somehow shield the instruments
from all kinds of disturbances such as
RFI (radio transmitters) and Static (electro static)
Charges and thermal changes.

Noise is the single most important thing
next to calibrating time marks.
But all of this is only my opinion
and not necessarily the absolute truth.

Regards;
geoff


----- Original Message ----- 
From: "Jerry Payton" 
To: "PSN-L" 
Sent: Sunday, September 17, 2006 8:00 AM
Subject: Metods for Improving SNR for events ??


> Is there a way or ways to improve the SNR (signal to noise ratio) of an 
> incoming event?
> 
> I realize that if the incoming rays are not strong enough, they will not 
> overcome the ambient noise of the system.
> 
> I would further assume that lowering the ambient noise is the best solution, 
> but I understand that can be a real challenge.  Personally, I live in a 
> wooded area, remote from vehicle travel and most man-made noises.  But, 
> weather and wind will affect my noise significantly......something I have to 
> live with.
> 
> My vertical and horizontal sensors are simply laying on a concrete floor in 
> an unattached garage with proper covers over each.  Any gain adjustments 
> raise or lower the noise factor directly.  I guess that finding a "happy 
> level" and living with it is my only solution.  But, if there are any 
> suggestions or remedies out there, I'd appreciate knowing about it..
> 
> Best Regards,
> Jerry Payton 
>
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