<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<p><tt>Author: Nacho Romero<br>
</tt></p>
<p><tt>Dear all,</tt></p>
<p><tt>Since the start of 2017 the "17g" Glonass navigation files
have been reporting epochs with an incorrect epoch, always wrong
by "1.0" second, this is due to an old version of teqc being
used for the generation of the "17g" files.</tt></p>
<p><tt>This comes about because the Glonass navigation files are in
UTC ...</tt> (thanks to Lou Estey for the explanation)<br>
see Table A11 ...
<a class="moz-txt-link-freetext"
href="https://igscb.jpl.nasa.gov/igscb/data/format/rinex211.txt">https://igscb.jpl.nasa.gov/igscb/data/format/rinex211.txt</a>
<br>
<br>
| TABLE
A11 |
<br>
| GLONASS NAVIGATION MESSAGE FILE - DATA RECORD
DESCRIPTION |
<br>
+--------------------+------------------------------------------+------------+
<br>
| OBS. RECORD | DESCRIPTION
| FORMAT |
<br>
+--------------------+------------------------------------------+------------+
<br>
<code class="moz-txt-verticalline"><span class="moz-txt-tag">|</span>PRN
/ EPOCH / SV CLK<span class="moz-txt-tag">|</span></code> -
Satellite number: | I2, |
<br>
| | Slot number in sat. constellation
| |
<br>
| | - Epoch of ephemerides (UTC)
| |
<br>
| | - year (2 digits, padded with 0,
| 1X,I2.2, |
<br>
| | if necessary)
| |
<br>
| | - month,day,hour,minute,
| 4(1X,I2), |
<br>
| | - second
| F5.1, |
<br>
<br>
i.e. the ephemeris time for a GLONASS navigation ephemeris is in
UTC. So if an older
<br>
version of teqc is being used, it does not know about recent leap
second insertions into
<br>
UTC.
</p>
<p><tt>If you operate a station with Glonass data and generate Rinex
2 Glonass navigation files please update your teqc version to
the latest one as found here;</tt></p>
<p><a class="moz-txt-link-freetext"
href="https://www.unavco.org/software/data-processing/teqc/teqc.html">https://www.unavco.org/software/data-processing/teqc/teqc.html</a></p>
<p><br>
</p>
<p>the affected stations in the CDDIS repository is as follows for a
recent day, if you see your station PLEASE update the teqc ASAP
since its affecting everyone using the "brdc..17g" files each day;</p>
<p>cebr0150.17g<br>
cedu0150.17g<br>
coco0150.17g<br>
darw0150.17g<br>
faa10150.17g<br>
hob20150.17g<br>
kat10150.17g<br>
kiru0150.17g<br>
kour0150.17g<br>
mac10150.17g<br>
mas10150.17g<br>
mgue0150.17g<br>
mobs0150.17g<br>
naur0150.17g<br>
nnor0150.17g<br>
redu0150.17g<br>
str10150.17g<br>
sydn0150.17g<br>
tlsg0150.17g<br>
tow20150.17g<br>
vill0150.17g<br>
yar20150.17g<br>
yel20150.17g<br>
</p>
<br>
Thanks !!<br>
<pre class="moz-signature" cols="72">--
Best regards,
Nacho
_______________________________________________________________
Ignacio (Nacho) Romero
Aerospace Engineer, PhD
CSC Ltd @ ESA/ESOC/OPS-GN
Satellite Navigation Engineer @ ESOC Navigation Support Office
IGS Infrastructure Committee Chair
<a class="moz-txt-link-abbreviated" href="http://www.navigation-office.esa.int">www.navigation-office.esa.int</a>
<a class="moz-txt-link-abbreviated" href="http://www.canaryspaceconsulting.co.uk">www.canaryspaceconsulting.co.uk</a>
_______________________________________________________________
This message including any attachments may contain confidential
information, according to our Information Security Management System,
and intended solely for a specific individual to whom they are addressed.
Any unauthorised copy, disclosure or distribution of this message
is strictly forbidden. If you have received this transmission in error,
please notify the sender immediately and delete it.</pre>
</body>
</html>