Subject: [IGSMAIL-2253] Rollover testing & the IGS
From: Angelyn Moore
Date: Wed, 28 Apr 1999 13:37:47 PDT

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IGS Electronic Mail      Wed Apr 28 13:37:47 PDT 1999      Message Number 2253
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Author: Angelyn Moore
Subject: Rollover testing & the IGS

Dear IGS Colleagues,

Since more rollover-type testing is in the works, it seems timely to
send out a reminder of the availability of GPS status messages.  
You can find these at http://www.navcen.uscg.mil/gps/status 
(click on "Active NANU's").  We have the NANUs on the IGSCB ftp site,
but they are currently updated only once per day.

The PRN27 testing for d119 (29 APR 1999) has been cancelled (and
apparently rescheduled for 1 MAY 1999).  We have been informed of more 
such tests on different satellites in the future:

> The current GPS Y2K Operational Evaluation Test only involves SVN-27.
> There
> are three more  (counting today's)  test activities planned:  April 27,
> 0730 - 2130 Z;  April 29,  time TBD;  and May 1, 0730 - 2130 Z.  This
> series
> of tests covers the GPS Block II / IIA satellites.  Similar tests will be
> conducted in late May / early June on the Block IIR series.
>
> The tests are looking at the three upcoming events:  GPS EPOCH rollover;
> Y2K Leap Year/Second issue;  and Y2K Rollover.  Basically, SVN-27 is taken
> out of service (set "unhealthy"), the clock ran up to simulate the
> particular event, then appropriate system tests and checks are made.
>
> These tests will be transparent unless the GPS receivers are not SPS
> Signal
> Spec / GPS ICD 200 compliant, and/or the unhealthy bit is purposely being
> ignored.
>
> (Supplied by Hank Skalski)

IGS operators are urged to keep informed of current NANUs.   It is 
recommended that operators whose stations are subject to hanging during
future date testing disable tracking during the affected times when
satellites are known to be involved in testing of future time periods.

All Allen Osborne Associates geodetic receivers are likely to require
a flashcard erase if data from a satellite broadcasting future date data
is recorded onto the flashcard.  If you have experienced problems which
seem to be related to rollover testing with other IGS receivers, I would
appreciate receiving a brief summary by email.

Best regards,
Angie
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Angelyn W. Moore, Ph.D.              Deputy Director, IGS Central Bureau 
 JPL/Caltech                                 [email-masked]
 4800 Oak Grove Dr. MS 238-540                     voice: +1 818 354 5434 
 Pasadena CA 91109 USA   http://igscb.jpl.nasa.gov   fax: +1 818 393 6686

[Mailed From: "Angelyn W. Moore" <[email-masked]>]