MIME-Version: 1.0
From: Domenico IZ7SLZ <iz7slz.domenico@gmail.com>
Date: Wed, 27 Feb 2019 01:16:16 +0100
Message-ID: <CAC+C6w4vGhOm8tu6TmMsR4WEwRQO+ffHVccQcXV9pL-R2Ska-g@mail.gmail.com>
Subject: LF: 6th april 2019 : gps week rollover
To: "rsgb_lf_group@blacksheep.org" <rsgb_lf_group@blacksheep.org>
Content-Type: multipart/alternative; boundary="000000000000c7adc40582d51506"
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org

--000000000000c7adc40582d51506
Content-Type: text/plain; charset="UTF-8"

The GPS Week Number parameter is a ten-bit value in the range 0-1023,
repeating every 1024 weeks. Every gps converts the week number in UTC date.
Week 0 started at 00:00:00 UTC on Sunday, 6th January 1980, so the week
number 'rolled over' from 1023 to 0 at 23:59:47 UTC on Saturday, 21st
August 1999.
This week number rollover will occur again now on the 6th April 2019.
For sure, many of the old gps models, after the reset, will report a wrong
date.
BTW 1pps or 10 kHz references should be accurate as usual.

A new neo8 gps has been already ordered to replace the ancient Jupiter gps
wich actually synchronize my EbNaut linux pc clock by means of its 'binary
protocol' strings and 1pps via the programs 'gpsd' and 'chrony'.

In the industrial world, this rollover will cause certainly many issues. My
jupiter, for istance, comes from a old ship's AIS (automatic identification
system). This mandatory transponder is a safety equipment onboard that
communicates, via a VHF link, the own ship position and receives the
position of the other ships in the range. Many of old transponders equipped
with the same Jupiter gps , are still operational onboard, so for these
installations there will be a problem at least in showing the correct date
of the reports, but more serious failures could be observed.

73, Domenico IZ7SLZ

--000000000000c7adc40582d51506
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div style=3D"white-space:pre-wrap"><br>=C2=A0<br>=C2=A0<br>The GPS Week Nu=
mber parameter is a ten-bit value in the range 0-1023, repeating every 1024=
 weeks. Every gps converts the week number in UTC date. Week 0 started at 0=
0:00:00 UTC on Sunday, 6th January 1980, so the week number &#39;rolled ove=
r&#39; from 1023 to 0 at 23:59:47 UTC on Saturday, 21st August 1999. <br>Th=
is week number rollover will occur again now on the 6th April 2019.<br>For =
sure, many of the old gps models,  after the reset,  will report a wrong da=
te.<br>BTW  1pps or 10 kHz references should be accurate as usual.<br><br>A=
 new neo8 gps has been already ordered to replace the ancient Jupiter gps w=
ich  actually synchronize my EbNaut linux pc clock by means of its &#39;bin=
ary protocol&#39; strings and 1pps via the programs &#39;gpsd&#39; and &#39=
;chrony&#39;.<br><br>In the industrial world,  this rollover will cause cer=
tainly many issues. My  jupiter, for istance, comes from a old ship&#39;s A=
IS (automatic identification system). This mandatory transponder is a safet=
y equipment onboard  that communicates, via a VHF link,  the own ship posit=
ion and receives the position of the other ships in the range. Many of old =
transponders equipped with the same Jupiter gps , are still operational onb=
oard, so for these installations there will be a problem at least in showin=
g the correct date of the reports, but more serious failures could be obser=
ved.<br><br>73, Domenico IZ7SLZ<br><br><br><br><br><br><br></div>

--000000000000c7adc40582d51506--