Another timing option if you cannot get a good WWV signal or if your GPS
signal is blocked by surrounding terrain, buildings, vegetation, etc, is
Tardis 2000. This is best used with a continuous internet connection or at
least you could set it up so it checks the timing while you are recording
data. It connects at pre-determined time intervals to various timing
locations around the globe of your choosing and updates your computer
timing. It sells for $20 (US), and here is the link to their web site:
http://www.kaska.demon.co.uk/
I used this for 3 years before we moved to a location where I could use GPS.
I found it to be highly reliable and did not have any problems with it.
Bob Hancock
Three Points, AZ
_____
From: psn-l-request@.............. [mailto:psn-l-request@............... On
Behalf Of ChrisAtUpw@.......
Sent: Saturday, April 21, 2007 08:35
To: psn-l@..............
Subject: Re: Time of Quake??
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
Another timing option if you cannot =
get a
good WWV signal or if your GPS signal is blocked by surrounding terrain,
buildings, vegetation, etc, is Tardis 2000. This is best used with =
a
continuous internet connection or at least you could set it up so it =
checks the
timing while you are recording data. It connects at pre-determined =
time
intervals to various timing locations around the globe of your choosing =
and updates
your computer timing. It sells for $20 (US), and here is the link =
to
their web site: http://www.kaska.demon.co.uk/<=
o:p>
I used this for 3 years before we =
moved to
a location where I could use GPS. I found it to be highly reliable =
and did
not have any problems with it.
Bob =
Hancock
Three Points, =
AZ
From:
psn-l-request@.............. [mailto:psn-l-request@............... =
On Behalf Of =
ChrisAtUpw@.......
Sent: Saturday, April 21, =
2007
08:35
To: =
psn-l@..............
Subject: Re: Time of =
Quake??
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/nei=
s/travel_times/
and also download =
tables
and charts to measure the distance from the P to S delay time.
Regards,
Chris Chapman