[IGSMAIL-5746]: RINEX files with missing C2 observations on CDDIS

[Rodrigo Leandro]

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IGS Electronic Mail      30 Mar 12:30:42 PDT 2008      Message Number 5746
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Author: Rodrigo Leandro
        Richard Langley
        Liliana Sukeova
        Marcelo Santos

Dear colleagues:

It has come to our attention that there are a number of stations whose RINEX
hourly/daily files are being submitted to CDDIS with the header indicating
that the file contains L2C code measurements ("C2" in RINEX 2.11
nomenclature), but with no such observations in the data records (i.e., the
slots related to C2 are empty). But these files are flagged as "L2C station
files" in the CDDIS L2C report (see e.g.,
ftp://cddis.gsfc.nasa.gov/reports/gps/daily/l2c_summary.current) which is
causing confusion.

This is a problem particularly for those using these data files for L2C
signal
analysis. We would like to ask the operators of the stations listed in the
CDDIS report to check if the files indeed contain L2C code measurements. If
they do not, either reconfigure or replace the RINEX-generating software or
remove C2 from the header (for example using TEQC -
http://facility.unavco.org/software/teqc/teqc.html) so that the station will
no longer wrongly appear in the L2C station report.

A related problem we have noticed is that some stations have submitted RINEX
2.10 files from L2C-capable receivers with the C2 observations appearing in
the P2-observation slots for IIR-M satellites. Stations submitting such
files
are welcome to use a RINEX 2.10 to 2.11 converter developed at UNB (which is
available at: http://gaps.gge.unb.ca/R210to211.zip) to fix the files and
have
them in an appropriate RINEX 2.11 format.

There are a couple of other L2C-related issues we would like to raise but
we'll deal with those in a subsequent message.

Thanks and best regards,

Rodrigo Leandro
Richard Langley
Liliana Sukeova
Marcelo Santos


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Rodrigo Leandro 
Trimble Geomatics and Engineering Group 
Trimble Terrasat GmbH 
Haringstr. 19 - 85635 Hoehenkirchen - Germany 
Tel.: +49 (0) 8102 7433 0 - Fax: +49 (0) 8102 7433131 
E-mail: Rodrigo_Leandro at trimble.com 
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