Re: [gpsd-users] GPS Time Synchronization

[John Klug]

ntpd is what we use.  crony is also a possibility.  The PPS and GPS information 
are in separate shared memory locations, and with ntpd, these are configured as 
IP addresses.

Here is our ntp.conf patch file for default ntp usage:
http://git.multitech.net/cgi-bin/cgit.cgi/meta-mlinux.git/tree/recipes-support/ntp/files/ntp.conf.patch

John Klug
Senior Software Engineer

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________________________________
________________________________
From: gpsd-users address@hidden on behalf of Burton, John address@hidden
Sent: Thursday, May 18, 2017 6:21 PM
To: address@hidden
Subject: [gpsd-users] GPS Time Synchronization

Hi All!
I have what might or might not be an easy question.

  *   I have a computer running RedHat Enterprise Linux 7.3 that has GPS 
reciever attached to it that also provides a PPS signal. This computer is used 
as a real-time data acquisition system.
  *   I have configured the computer as described in 
http://catb.org/gpsd/gpsd-time-service-howto.html<http://mail2.multitech.com:32224/?dmVyPTEuMDAxJiZmNGMyMWQ1OTU4MTk2ZWViNj01OTFFMkM4Ml82NTIwMF85MTlfMSYmNjE3ZWE3MjRiMWVhNjEyPTEzMzMmJnVybD1odHRwJTNBJTJGJTJGY2F0YiUyRW9yZyUyRmdwc2QlMkZncHNkLXRpbWUtc2VydmljZS1ob3d0byUyRWh0bWw=>
 to operate as a network clock. This works fine.
  *   One of the devices I am capturing data from is an INS/GPS system that 
provides a position and pointing data packet with a GPS timestamp (week since 
GPS epoch + seconds into the week).
  *   I also have other devices that I am acquiring data for that I am 
attaching a timestamp to. I am currently using the 
boost::chrono::system_clock::now().
  *   I need to have all captured data using the same clock basis for the 
timestamp.
  *   How do I get GPS timestamp from my system clock?

John

--

John Burton, Ph.D.
MTEQ, Inc.

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Lorton, VA 22079-2630                      Mobile: 757-508-6208
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