| Description: | During the ENA deployment, the UHSAS instrument clock was not synced with a time server. I
used a comparison of the peaks in the UHSAS data and the CPC or the PSAP data to
determine how far off the clock was. The UHSAS was always within ~2 minutes of the other
instruments and the CPU it was attached to. Starting from 2/18/2014 the UHSAS was ~ 45
seconds. slow. It gradually got faster and around 6/2014 it was within seconds of the CPC. It
continued in that direction and gradually became slower than the CPC or PSAP. On
1/22/2015 the UHSAS was ~120 seconds slower than the PSAP. At 16:05:00 1/22/2015 the UHSAS time
was manually set to the Unit 2 CPU time. This was done remotely and apparantly only to
within about 20 seconds.
A Document shows the times of the peaks used to determine the time
difference.
During 2015 until the Domain time II was installed on 07/25/2016 the UHSAS was synced
manually about once a month. Between syncs it generally drifted slow. During the period
until 06/24/2015 the monthly correction was less than 20 seconds. There was a gap in the
corrections and on 10/21/2015 it was corrected from 1 minute 22 seconds slow. The
corrections after that were from about 15 to 35 seconds slow. The first time sync after Domain
time II was installed corrected the time from 1 minute 12 seconds slow. |