In a message dated 2007/04/21, Paulc@........ writes:

    > For the past month I have been working on a horizontal pendulum sensor 
> and I am going through my maiden voyage with it.
>     The clock is accurate to within 10 seconds, I am using the Amaseis 
> program, and a 12 bit ADC.

Hi Paul,

       The P waves may travel at 8.2 km / sec. You need your clock accurate 
to about 1 sec for practical purposes. I suggest that you keep a note of the 
errors for a day or two. They are often very large.
       You can buy a radio corrected crystal clock for less than $20. They 
are very useful and are accurate to 20 mS. They update every hour. 
       You can also visit http://nist.time.gov/ and cross check on-line, but 
do watch out for transient data delays.

>     I would like to try and compare events elsewhere in the world / country 
> to my sensor. At this site I can see various locations.
>  
> The question.
>  
>     If I know in  when in UTC an event occurred, and where.. how do I 
> convert that to a UTC time when the event would arrive at my location, if ever.
> In other words how ho long does it take to get here??

   Y> ou can calculate arrival time using 
> http://neic.usgs.gov/neis/travel_times/ 
> 
       and also download tables and charts to measure the distance from the P 
to S delay time.

       Regards,

       Chris Chapman

   
In a me=
ssage dated 2007/04/21, Paulc@........ writes:



    
For the=20=
past month I have been working on a horizontal pendulum sensor and I am goin=
g through my maiden voyage with it.

    The clock is accurate to within 10 seconds, I am using t=
he Amaseis program, and a 12 bit ADC.




Hi Paul,



       The P waves may travel at 8.2 km / sec.=
 You need your clock accurate to about 1 sec for practical purposes. I sugge=
st that you keep a note of the errors for a day or two. They are often very=20=
large.

       You can buy a radio corrected crystal c=
lock for less than $20. They are very useful and are accurate to 20 mS. They=
 update every hour. 

       You can also visit http://nist.time.gov=
/ and cross check on-line, but do watch out for transient data delays.



    I would lik=
e to try and compare events elsewhere in the world / country to my sensor. A=
t this site I can see various locations.

 

The question.

 

    If I know in  when in UTC an event occurred, and wh=
ere.. how do I convert that to a UTC time when the event would arrive at my=20=
location, if ever.

In other words how ho long does it take to get here??




   Y
ou can calculat=
e arrival time using htt=
p://neic.usgs.gov/neis/travel_times/ 



       and also download tables and charts=
 to measure the distance from the P to S delay time.



       Regards,



       Chris Chapman