Delivered-To: igsmail@igscb.jpl.nasa.gov
Message-ID: <5ACEEE96F4F9D41190790002A528B51E03BD6125@s0-ott-x11.nrn.nrcan.gc.ca>
From: "Delahunt, Stephen" <sdelahun@nrcan.gc.ca>
To: "IGSMAIL (E-mail)" <igsmail@igscb.jpl.nasa.gov>
Cc: "ACS-OP (E-mail)" <ACS-OP@geod.nrcan.gc.ca>,
	"Helpdesk, GPSC" <ess-gsd-gpschelp@NRCan.gc.ca>
Subject: [IGSMAIL-4406]: NRC1: Clock Change MID-DAY - 15:00 UTC, 03May28 (DOY148)
Date: Wed, 28 May 2003 15:26:21 -0400
Sender: owner-igsmail
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******************************************************************************
IGS Electronic Mail      28 May 12:26:26 PDT 2003      Message Number 4406
******************************************************************************

Author: Stephen M. Delahunt

IGS Site:   NRC1
DOMES # 40114M001
Agency:    Natural Resources Canada (NRCan) ...formerly EMR
Location:   Ottawa, Ontario
Country:    CANADA

ADVISORY: The current Hydrogen Maser clock was taken off-line at 15:00 UTC,
03May28 (DOY148).
                   NRC1 data for the remainder of 03May28 (DOY148) will not
be submitted to the IGS.
                   Hourly data submissions will resume tomorrow 03May29
(DOY149).
                   A different Hydrogen Maser clock was introduced at this
site, between 15:00 and 16:00 UTC.
                   Tracking was not terminated and between active-maser
disconnect/reconnect the receiver 
                   tracked using internal crystal with clock steering.  

RECOMMENDATION:  Do not use NRC1 data for 03May28 (DOY148), beyond 15:00 UTC