PSN-L Email List Message

Subject: Re: Time of Quake??
From: Stephen & Kathy skmort@............
Date: Sat, 21 Apr 2007 13:24:12 -0700


FYI,,  you are correct,,  exact timing is only important to the pros and 
those who are trying to use their own traces in conjunction with others 
to find exact start time of the event, exact location and magnitude!   
If you plan to send your files to PSN for others to use and analyze, 
then you need to get serious about better timing, otherwise just 
enjoy,,,   your relative P and S times will still give you the distance 
from your station and you can still determine a magnitude based on your 
station parameters, but trying to correlate your trace with others 
becomes a bit of a pain!   If you know your timing error, some of the 
viewing software, (like winquake), allows some shifting of the time 
after the fact!   I use the old Radio Shack version of dataq, the 12 bit 
DI-150RS, in conjunction with Amaseis software,,,   my system gains 
about 13 seconds per day and I use Atomic time, (over a phone line), to 
reset once per day and then it is set to compensate each hour,,,  but it 
only compensates after it is out by at least one second, which means it 
only compensates about every two hours!   Once in a while, atomic time 
will hang and I won't notice it for several days,,,,   it is just a 
hobby for me so timing isn't critical, or serious!!!!   I do have a 
fixed GPS and for a while, when I was running the dataq software, I let 
it record time hacks on the second channel and could easily determine my 
error!  
  Stephen
  PSN Station #55
  where dumb mistakes are a regular part of my adventure in life, ha!!

Paul Cianciolo wrote:
> Hey Guys,
>
> Thanks for all the input on the time question.
>
> First I did make a mistake, as Steven pointed out.  Thanks Steve...  Yup I
> was adding the time..  Sorry for the dumb mistake.
>
> I am going to check out the links that you folks pointed out.
>
> I also have a 10 MHz GPS discipline standard... a Z3801  and will look into
> interfacing that to my computer.
>
> But will somebody please tell me why the clock accuracy is so important??
> It appears that events last multiples of minutes and longer.  Why is clock
> accuracy in milliseconds so important.
> Unless one is trying to "triangulate" or compare phase of signals.. I must
> be missing something.
>
> PauLC
> W1VLF
>
>   
>   



  
  


FYI,,  you are correct,,  exact
timing is only important to the pros and those who are trying to use
their own traces in conjunction with others to find exact start time of
the event, exact location and magnitude!   If you plan to send your
files to PSN for others to use and analyze, then you need to get
serious about better timing, otherwise just enjoy,,,   your relative P
and S times will still give you the distance from your station and you
can still determine a magnitude based on your station parameters, but
trying to correlate your trace with others becomes a bit of a pain!  
If you know your timing error, some of the viewing software, (like
winquake), allows some shifting of the time after the fact!   I use the
old Radio Shack version of dataq, the 12 bit DI-150RS, in conjunction
with Amaseis software,,,   my system gains about 13 seconds per day and
I use Atomic time, (over a phone line), to reset once per day and then
it is set to compensate each hour,,,  but it only compensates after it
is out by at least one second, which means it only compensates about
every two hours!   Once in a while, atomic time will hang and I won't
notice it for several days,,,,   it is just a hobby for me so timing
isn't critical, or serious!!!!   I do have a fixed GPS and for a while,
when I was running the dataq software, I let it record time hacks on
the second channel and could easily determine my error!   
  Stephen
  PSN Station #55
  where dumb mistakes are a regular part of my adventure in life, ha!!

Paul Cianciolo wrote:
Hey Guys,

Thanks for all the input on the time question.

First I did make a mistake, as Steven pointed out.  Thanks Steve...  Yup I
was adding the time..  Sorry for the dumb mistake.

I am going to check out the links that you folks pointed out.

I also have a 10 MHz GPS discipline standard... a Z3801  and will look into
interfacing that to my computer.

But will somebody please tell me why the clock accuracy is so important??
It appears that events last multiples of minutes and longer.  Why is clock
accuracy in milliseconds so important.
Unless one is trying to "triangulate" or compare phase of signals.. I must
be missing something.

PauLC
W1VLF

  
  

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