Subject: [IGSMAIL-2918]: use of teqc w/ TurboRouge formats
From: Lou Estey <[email-masked]>
To: [email-masked]
Cc: [email-masked]
Date: Fri, 7 Jul 2000 16:30:39 -0600 (MDT)

******************************************************************************
IGS Electronic Mail      07 Jul 15:47:28 PDT 2000      Message Number 2918
******************************************************************************

Author: Lou Estey

This is a notice to anyone in the IGS using teqc to translate
TurboRouge ConanBinary or TurboBinary formats into RINEX.
Otherwise, please ignore and delete.

-----------------------------

There is a bug in all past versions of teqc which decode the
raw binary 72-byte navigation message available in certain
formats, including ConanBinary and TurboBinary, from subframes
1-2, words 3-10 of the original SV broadcast navigation messages.
If you are interested, more about the background on this can
be found at:

	http://www.unavco.ucar.edu/html_mail/teqc/msg00129.html
	http://www.unavco.ucar.edu/html_mail/teqc/msg00131.html
	http://www.unavco.ucar.edu/html_mail/teqc/msg00132.html
	
The bug introduces bogus ionospheric alpha and beta model parameters
into the RINEX NAV header, based on an obsolete (circa 1980)
interpretation of the construction of the navigation message.  The
code fix is simply to ignore that portion of the message, which is
currently defined as "reserved" bytes.

If anyone is interested, I can quickly supply a version of teqc
with the fix for most all supported UNIX/Linux builds.  If you
are using teqc on a UNIX or Linux system and want to get cleaner
RINEX NAV files before the next official release of teqc (time
frame unknown), execute "teqc +id" and send me the result before
13 July.  Then I'll do a limited teqc release with the fix for
the requested operating systems and send out another email.

A final note: The iono alpha and beta parameters from any
archived RINEX files created by any teqc version prior to
31 May 2000 from TurboRouge data are probably bogus and should
not be used.

Sorry for any inconvenience this has caused.

Best regards,
--lou
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Louis H. Estey, Ph.D.              office:  (303)497-8036      
UNAVCO/GST/UCAR, P.O. Box 3000        FAX:  (303)497-8028
Boulder, CO  80307-3000            e-mail:  [email-masked]
   websites: http://www.gst.ucar.edu http://www.unavco.ucar.edu

"If the universe is the answer, what is the question?"
                                               -- Leon Lederman
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~