PSN-L Email List Message

Subject: Re: Is our quake time correct?
From: Jim Hannon jmhannon@.........
Date: Wed, 21 Dec 2011 16:45:01 -0600


Here is a good explanation of the situation.
http://gpsinformation.net/main/gpstime.htm
Basically there should be no problem as the receiver should read the UTC 
offset information and correct. Especially a receiver that has been 
running all along.


On 12/21/2011 2:01 PM, Gary Gibson wrote:
> It is not a problem George. The seconds correction is sent with the GPS
> signal and most systems apply it eaprautomatically to get UTC. In some
> of the older systems it had to be set by the operator. An error of 15
> seconds would be very obvious when locating earthquakes. Much more
> difficult is an error of 1 second due to poor software or hardware on
> some ch
>
> Sent from my iPhone
>
> On 22/12/2011, at 6:39 AM, George Bush  > wrote:
>
>> I just heard that the UTC time and the GPS time are about 15 seconds
>> different.
>>
>> I subscribe to the _NewScientist_ magazine and in the 17 Dec 2011
>> issue, p. 27 was a report _One minute with Felicitas Arias_, who is
>> the director of the time department at the International Bureau of
>> Weights and Measures in Paris. She was discussing how the UTC time is
>> 'adjusted' in 1-second intervals for a closer match to astronomical
>> time while the clocks in the GPS satellites need a continuous time
>> scale and do not use the 'adjusted' seconds and so the GPS and the UTC
>> are slowly drifting apart!
>>
>> If true, this could have major implications for the amateur stations
>> that rely on a GPS receiver for the correct time. Maybe the receivers
>> adjust the time before outputting it to us, I don't know.
>>
>> Does anybody else know about this and if it is a problem to us?
>>
>> George
>>

-- 
WB0TXL
WEB Page http://www.fmtcs.com/web/jmhannon/
Blog http://jimhannon.wordpress.com
42,11.90N,91,39.26W

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