PSN-L Email List Message

Subject: Re: Questions
From: "Geoffrey" gmvoeth@...........
Date: Wed, 18 Oct 2006 04:52:24 -0700

Hello Ted;

The file 061017.013725.ebgz.psn
is way too noisy. The gain should be reduced
to the point where noise is only +/- a few counts.

This signal reminds me of the Hawaii quake
I received but instead of getting any S wave
I just got two "P" waves (Main event/aftershock) and what seemed
to be followed by surface waves.

I have found that Winquake does not want me to
start my converted files on a decimal point
I must start my files on an exact second start
point to get correct times.

If I start my files in the middle of a second
it will offset all the measured times with an error by the
decimal amount.

Winquake seems to ignore fractional values smaller than the whole second at the start of a data set.

Dont know if I am clear here.


----- Original Message ----- 
From: "tchannel" 
Sent: Tuesday, October 17, 2006 11:30 AM
Subject: Questions

I have finished my sensor, and have had it running for three days.

1.  During the night hours, 11pm to 6am, the tract goes from normal to noisy, getting worse each hour.  The sensor sits in the 
garage on a concrete slab.  No draft and no heat.  As soon as I go into the garage in the AM and the room gets warmer, because the 
sun warms the room to about 60 f. The trace returns to normal.  Is this temperature effect?  I also turn off the monitor and turn it 
back on in the AM.  Could the CTR or the computer create noise? They set about three feet from the sensor. Again no heat, no draft 
and nothing running out there in the night.

2.   I think I am getting a good recording, I have see the last two quakes and to me they look normal.
I am in Boise Idaho and have tried to compare my .PSN with any others close by.  However our local one in Boise is down and the 
next, nearest one is in Washington State.   Now here is a hard question to ask:  I created my expanded trace, using the same time 
plotted on the .PSN in Washington (061017.013725.ebgz.psn M6.5 10356km from Ellensburg, Wa.,) This was around one hour of trace.  I 
did this so I could compare the two side by side.  I was a little surprised to see the Wa. psn to show a large spike on the P and a 
short spike on the S.  My trace looks very similar, but I show a large spike on the S and a smaller spike on the P.   From the 
description of the Ellensburg Wa file it has a Z in it, is that a Vertical sensor? and since my sensor is a Horz pointing N/S, would 
that explain the different. These events came from the East, and I have my beam pointing North.
Anyone who would like me to send both .PSN's to them for a critique, please email me.   I would appreciate someone looking at them 
and voicing an opinion as to my level of gain, not sure if it is correct, and some advise as to how to best filter this event to 
enhance the P and S. I am just using trial and error.

3.  Presently I am building a Plexiglas box.  But would it help to reduce noise if I built a second box wrapped with alum foil?   Or 
other ideas on building a box which would make a positive different?

4.   I know weather can alter the way the trace looks, I thought my situation was weather, but it was clear today.
What is there in a front moving thru that creates the noise?   Lets say a front with little wind and no lightening.

Many thanks, Ted 


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