## PSN-L Email List Message

Subject: Re: Signal To Noise Ratio
From: Bob Hancock carpediem1@.........
Date: Sat, 03 Nov 2007 17:06:31 -0700

```Hi Geoff -

Unfortunately, my knowledge of electronics is less than stellar.  I am
working at understanding concepts of seismology.  As for
electronics.....well, I'll leave that for someone else.  I was hoping to
find an answer that would allow me to apply the SNR numbers I see to the
practical side of seismology.  I understand the simple concept of an
amplifier (boosting a signal), but unfortunately, I have no working
knowledge of their innards or how the individual parts work by themselves
and in concert with each other.

Bob H

On 11/3/07 4:50 PM, "Geoff"  wrote:

> Hello Bob;
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> Have you ever heard of a low noise
> GaAs op amp that is designed to work
> like a op177G (typical opamp) or ??
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> Signal to noise ratio should be easily found
> in google I think it simply is like
> Expectided MDL signal power / Ubiquitous Noise Power
> The higher the ratio the better the whatever.
> Possibly expressed in db.
> For power thats 10Log(Sig/Noi).
> The noise would be the reference point.
> If you can get a 120db (coopers)
> I think youd be in fat city.
> The higher the overall s/n ratio
> the smaller signals they can see.
> Like someone sneezing next door.
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> :-)
> geoff
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> ----- Original Message -----
> From: "Bob Hancock"
> To: "PSN"
> Sent: Saturday, November 03, 2007 1:16 PM
> Subject: Signal To Noise Ratio
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ted
> the signal to noise ratio.  Most of the time the number was =AD1; however,
> there were other numbers listed.  I have some questions and hopefully
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> 1.  What is the significance of signal to noise ratio when looking at
> earthquakes?
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> 2.  How is signal to noise ratio computed?
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> 3.  What are the ideal numbers to look for and at what point does the dat=
a
> become unusable?
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> Thanks
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> Bob Hancock
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