From bill@tycho.usnogps.navy.mil Wed May 5 07:18:40 EDT 1999
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From: Bill Bollwerk
Message-Id: <199905051116.LAA09587@tycho.usnogps.navy.mil>
Subject: AMC2 TR 1pps Step
To: jimr@maia.usno.navy.mil (Jim Ray)
Date: Wed, 05 May 1999 11:16:43 UTC
Cc: linda@gracie.grdl.noaa.gov, sth@tycho.usnogps.navy.mil
X-Mailer: Elm [revision: 212.4]
Status: RO
Jim,
The TR took another step in it's 1 pps measurement yesterday at MJD 51302.01.
The 1 pps measurement took a step increase and has remained at the new value
for over 24 hours.
It looks like we may need S/N 245 back from AOA, that is if they have
determined and corrected the source of these anomalies with the 1 pps.
Bill
From linda@lynx.grdl.noaa.gov Wed May 5 07:38:07 EDT 1999
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From: linda@lynx.grdl.noaa.gov
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Message-Id: <199905051136.HAA02649@lynx.grdl.noaa.gov>
Subject: Re: update on AOA receiver at Schriever AFB
To: jimr@maia.usno.navy.mil (Jim Ray)
Date: Wed, 05 May 1999 7:36:14 EDT
Cc: bill@tycho.usno.gps.navy.mil
In-Reply-To: <199905041650.MAA17226@maia.usno.navy.mil>; from "Jim Ray" at May 04, 99 12:50 (noon)
X-Mailer: Elm [revision: 212.4]
Status: RO
Hi Jim,
You can add another day to that list of yours. The reciever at
AMC2 stopped tracking, for no apparent reason, on day 124
at 00:09 UTC.
I started tracking manually at approximately 11:00 UTC.
-Linda
------------------------------------------------------------------------
Linda Nussear Geosciences Laboratory/NGS/NOS/NOAA
e-mail: linda@lynx.grdl.noaa.gov SSMC III, STA. 9111B
phone : 301-713-2845 1315 East-West Hwy
fax : 301-713-4475 Silver Spring MD 20910
------------------------------------------------------------------------
From jimr Wed May 5 09:31:19 EDT 1999
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From: Jim Ray (USNO 202-762-1444)
Message-Id: <199905051331.JAA28149@maia.usno.navy.mil>
Subject: 247-U at Schriever AFB
To: djkforaoa@aol.com (Don Kennedy (AOA)),
aoa@aoa-gps.com (Allen Osborne Assoc.)
Date: Wed, 05 May 1999 9:31:18 EDT
Cc: bill@tycho.usnogps.navy.mil (Bill Bollwerk (USNO/TS)),
sth@tycho.usnogps.navy.mil (Steven Hutsell (USNO/TS)),
paul@tsee2.usno.navy.mil (Paul Wheeler (USNO/TS)),
miranda@tango.grdl.noaa.gov (Miranda Chin (NOAA/CIGNET)),
linda@gracie.grdl.noaa.gov (Linda Nussear (NOAA/CIGNET)),
jimr@maia.usno.navy.mil
X-Mailer: Elm [revision: 212.4]
Status: RO
ATTN: Don Kennedy
Jim Holston
Yesterday, the USNO SNR-12 ACT receiver (S/N 247-U) recently installed at
Schriever AFB experienced another anomaly. So the history of problem
events is now:
* 26-Mar-99 spontaneous clock reset of +245 ns at ~01:10 UTC
* 31-Mar-99 receiver stopped tracking at ~00:10 UTC
* 09-Apr-99 receiver stopped tracking at ~00:09 UTC
* 30-Apr-99 spontaneous clock reset of -7625 ns at ~00:10 UTC
* 04-May-99 receiver stopped tracking at ~00:09 UTC
I conclude that there is a definite problem with unit 247-U.
Based on this experience, please ship the SNR-12 ACT receiver (S/N 245-U)
which is ready for shipment at AOA, to Colorado Springs rather than to
USNO, Washington, as orginally planned. We will then return 247-U to
AOA for repair.
The shipping address for unit 245-U is:
Bill Bollwerk (719) 567-6740
USNO AMC
400 O'Malley Avenue
Suite 44
Schriever AFB, CO 80912-4044
Thanks,
--Jim
=========================================================================
Jim Ray e-mail: jimr@maia.usno.navy.mil
U.S. Naval Observatory, EO Dept. phone : 202-762-1444
3450 Massachusetts Avenue, NW fax : 202-762-1563
Washington, DC 20392-5420
=========================================================================