[IGSMAIL-5888]: IGL SP3 header change

[Jim.Ray]

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IGS Electronic Mail      21 Jan 10:46:18 PST 2009      Message Number 5888
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Author: Jim Ray

A very longstanding format error in the IGS GLONASS
SP3 product files -- those with names of the form
iglWWWWd.sp3 -- was recently reported to us.  Header
line 13 of each SP3 file has read:

%R G  cc GPS ccc cccc cccc cccc cccc ccccc ccccc ccccc ccccc

whereas the correct syntax should be:

%c R  cc GPS ccc cccc cccc cccc cccc ccccc ccccc ccccc ccccc

where R/G in column 4 signifies "GLONASS" or "GPS"
respectively.

It seems that this error has existed for at least several
years.  Evidently most user software does not actually pay
close attention to this comment line.

Unless we hear immediate objections, this error will be
fixed in the IGLOS orbit products for week 1513, which will
be distributed tomorrow (22 Jan 2009).

We thank Steve Hilla for bringing this error to our attention.