PSN-L Email List Message

Subject: High noise >10s
From: "Tiago A." tiagoagre@.........
Date: Mon, 30 Jul 2012 02:07:57 +0000


Hi.

Im using a L4 1Hz geophone and for almost a month im struggling with high
noise from 10s up to ..., but from <10s it looks good. The noise comes and
goes, this image is self explaining:

http://dl.dropbox.com/u/15802004/noise.png

Changed cables, re centered the geophone, but didint help..the geophone is
connected directly to a ADC without damping, external amplification or
filtering, i only use digital filtering from the ADC. Before this issue
start, i had a pretty clean spectrum >10s for almost 6 months, which
allowed me to received LQ and LR from some strong events.

This sac contains 15minutes with high noise >10s, notice that at 3:37 it
recorded a Ml2.1 at 70km.
http://dl.dropbox.com/u/15802004/noise.sac

What could be the problem?

I appreciate any help.

Best Regards,
Tiago.
Hi.

Im using a L4 1Hz geophone and for almost a month im struggling = with high noise from 10s up to ..., but from <10s it looks good. The noi= se comes and goes, this image is self explaining:

http://dl.dropbox.com/u/15802004/noise= ..png

Changed cables, re centered the geophone, but didint help..the geophone= is connected directly to a ADC without damping, external amplification or = filtering, i only use digital filtering from the ADC. Before this issue sta= rt, i had a pretty clean spectrum >10s for almost 6 months, which allowe= d me to received LQ and LR from some strong events.

This sac contains 15minutes with high noise >10s, notice that at 3:3= 7 it recorded a Ml2.1 at 70km.
http://dl.dropbox.com/u/15802004/noise.sac

What co= uld be the problem?

I appreciate any help.

Best Regards,
Tiago.




[ Top ] [ Back ] [ Home Page ]