[IGSMAIL-4825]: updated P1-C1 bias values

[Jim Ray]

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IGS Electronic Mail      04 Feb 06:56:53 PST 2004      Message Number 4825
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Author: Jim Ray

Updated values for the <P1-C1> satellite biases are now available and
recommended for use by all IGS Analysis Centers and users of IGS clock
products beginning as soon as possible but not later than the start of
GPS week 1257:

      average <P1-C1> biases (ns) in PRN order (from PRN01 thru PNR40):

 h 2004 02 04
      data bias / -0.052d0, -1.096d0,  0.015d0,  1.383d0, -0.821d0,
     +             0.607d0, -0.942d0, -0.603d0,  0.392d0, -1.400d0,
     +             0.487d0, -9.999d9,  1.435d0,  0.180d0, -0.926d0,
     +            -0.517d0, -0.811d0, -0.066d0, -9.999d9, -1.109d0,
     +            -0.437d0,  0.374d0, -0.426d0,  0.337d0,  0.569d0,
     +             1.293d0, -0.062d0, -0.276d0,  0.785d0,  2.019d0,
     +            -0.333d0, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
     +            -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9  /

As with the previous set of biases (IGS Mail #4366, 06 May 2004), these
are based on the monthly average estimates by the CODE Analysis Center
for January 2004 (for background see IGS Mails #2827, 9 May 2000, and
#3212, 23 Feb 2001, by Stefan Schaer).

Please note that since the last update the constellation has changed
with the decommissioning of the old PRN22 on 06 Aug 2003 and its
replacement by the new IIR-10 satellite launched on 21 Dec 2003.
Consequently, the bias values for PRN22 are now quite different from
before.  PRN07 and PRN23 are the only others having bias changes
greater than 0.3 ns.

A new version of the program (cc2noncc Vers 4.5, 04 Feb 2004) and the
file of historic bias values (p1c1bias.hist) will be sent to the IGS
Central Bureau where they will be posted at
<ftp://igscb.jpl.nasa.gov/igscb/software/cc2noncc/>.

--Jim Ray