In a message dated 06/07/06, gpayton880@....... writes:

> Are you using a low pass filter on the graph that you have online ?
> Because there normally isn't a lot of noise below 5Hz.

> Yes, Lo setting is 0.10 with 2 poles and Hi setting is 0.05  with 2 poles.  
> Be advise that I am interested in teleseismic events, primarily.

Hi Jerry,

       If you view the trace with these filter selections, YOU WILL MISS the 
P & S waves which give you the earthquake timing. For these you need 
frequencies from 2 Hz to 0.5 Hz. The much larger long period Love waves are fine for 
picking up a quake.

> .  (My helicorder.gif is displayed on http://teleseismic.net/helicorders/ 
> at the bottom of the page from Springdale, AR)  

       The commoner non seismic signals are air convection noise, traffic and 
similar noise, sun / wind / draft / weather related noise and powerline 
interference. However, you may get combinations of these signals.

       FC1 from Friendswood Texas seems to be showing a lot of single pole / 
asymmetric signals. I wonder if this could be powerline problems?

       JL1 Hor at Spring Texas shows what appears to be chamber convection 
noise, starting at about 19.00 local and stopping about 5 - 6.00 after dawn. 

       JS2 from Houston Texas shows strong signals starting at about 7.00 and 
reducing after 13.00. Could this be air convection noise in a room which is 
heated by the morning sun?
       JS1 from Houston shows noise from about 7.00 and going on till late 
evening. Could this be traffic related?

> I also live away from normal traffic, but among a LOT of trees, which I am 
> told may cause a high noise level.  In short, I am told that it is normal and 
> is not for me to worry about.

       JP1 from Springdale shows noise from about midnight till 10.00. Could 
this be related to wind? Midnight seems late for the start of chamber air 
convection noise, but by no means impossible. Is this behavoir repeatable? 

       Have you though of getting a small weather station? It could keep 
track of the temperature changes and the wind speed and direction, which are 
likely to effect you with many trees nearby. The basic Davis starts at about $200. 
       If you have a spare channel on your ADC, you might buy a couple of 
photo diodes, connect them in parallel, but ~at right angles and record the 
daylight / sun intensity? (45 deg to the vertical on an E/W axis.) This could give 
you a fairly accurate indication of the solar heating. 
       I cut a hole in a ping-pong ball, stuck in a silicon photodiode with 
silicone rubber cement and mounted it vertically, where sunlight could reach it 
all day. The plastic ball acts as an 'integrating sphere' to give a near 
average light value, but it weathers slowly and needs to replaced once a year. It 
indicates dusk / dawn, whether it is cloudy or bright, etc. 
        You can also get a fairly good indication of sunpower by using two 
thermometers, one screened and that other painted black and placed in the sun.

       Regards,

       Chris Chapman



       
In a me=
ssage dated 06/07/06, gpayton880@....... writes:



Are you using a low pass filter=
 on the graph that you have online ?

Because there normally isn't a lot of noise below 5Hz.




Yes, Lo setting is 0.10 with 2=20=
poles and Hi setting is 0.05  with 2 poles.  Be advise that I am i=
nterested in teleseismic events, primarily.




Hi Jerry,



       If you view the trace with these filter=
 selections, YOU WILL MISS the P & S waves which give you the earthquake=
 timing. For these you need frequencies from 2 Hz to 0.5 Hz. The much larger=
 long period Love waves are fine for picking up a quake.



.  (My helicorder.gif is d=
isplayed on http://teleseism=
ic.net/helicorders/ at the bottom of the page from Springdale, AR) =
 




       The commoner non seismic signals are ai=
r convection noise, traffic and similar noise, sun / wind / draft / weather=20=
related noise and powerline interference. However, you may get combinations=20=
of these signals.



       FC1 from Friendswood Texas seems to be=20=
showing a lot of single pole / asymmetric signals. I wonder if this could be=
 powerline problems?



       JL1 Hor at Spring Texas shows what appe=
ars to be chamber convection noise, starting at about 19.00 local and stoppi=
ng about 5 - 6.00 after dawn. 



       JS2 from Houston Texas shows strong sig=
nals starting at about 7.00 and reducing after 13.00. Could this be air conv=
ection noise in a room which is heated by the morning sun?

       JS1 from Houston shows noise from about=
 7.00 and going on till late evening. Could this be traffic related?



I also live away from normal tr=
affic, but among a LOT of trees, which I am told may cause a high noise leve=
l.  In short, I am told that it is normal and is not for me to worry ab=
out.




       JP1 from Springdale shows noise from ab=
out midnight till 10.00. Could this be related to wind? Midnight seems late=20=
for the start of chamber air convection noise, but by no means impossible. I=
s this behavoir repeatable? 



       Have you though of getting a small weat=
her station? It could keep track of the temperature changes and the wind spe=
ed and direction, which are likely to effect you with many trees nearby. The=
 basic Davis starts at about $200. 

       If you have a spare channel on your ADC=
, you might buy a couple of photo diodes, connect them in parallel, but ~at=20=
right angles and record the daylight / sun intensity? (45 deg to the vertica=
l on an E/W axis.) This could give you a fairly accurate indication of the s=
olar heating. 

       I cut a hole in a ping-pong ball, stuck=
 in a silicon photodiode with silicone rubber cement and mounted it vertical=
ly, where sunlight could reach it all day. The plastic ball acts as an 'inte=
grating sphere' to give a near average light value, but it weathers slowly a=
nd needs to replaced once a year. It indicates dusk / dawn, whether it is cl=
oudy or bright, etc. 

        You can also get a fairly good in=
dication of sunpower by using two thermometers, one screened and that other=20=
painted black and placed in the sun.



       Regards,



       Chris Chapman