file: p1c1bias.hist
+cc2noncc/info
*============================================================================
This file contains the history of average biases values recommended
by the IGS for its Analysis Centers and for users of IGS products,
particularly those who use IGS clock products with a mix of receiver types
and where strict internal consistency is desired. For now, only GPS biases
are recognized (no GLONASS or other future GNSS systems).
For more complete background please refer to IGS Mail #2744 (15 Mar 2000)
and IGS Mail #2320 (24 Jun 1999).
The (C1,P2') pair available from cross-correlation style receivers (e.g.,
AOA TurboRogue and Trimble 4000) have satellite-dependent biases compared
with the (P1,P2) observables provided by newer generation receivers (e.g.,
Ashtech Z-XII, AOA Benchmark/ACT, etc). To avoid mixing data with different
satellite biases, which would degrade the IGS satellite clock products,
the IGS Analysis Centers have agreed to adopt a common pseudorange bias
convention by modifying data from the older receivers to be compatible with
the newer generation observables.
Specifically, this involves transforming data from cross-correlation style
receivers by:
C1 --> C1 + f(i) [becomes compatible with modern P1]
P2' --> P2'+ f(i) [becomes compatible with modern P2]
where f(i) are empirically-determined long-term average bias values
i for satellites PRNi. This transformation accounts for the
different satellite-based biases between cross-correlation pseudorange
observables (C1, P2') and the observables (P1, P2) reported by modern
Y-codeless receivers. In this way, a mixed network of receiver types can
be used together consistently.
In addition a few models of non-cross-correlator receivers (e.g., Leica
CRS1000) report C1 rather than P1. For these only C1 is replaced by
C1 --> C1 + f(i) [becomes compatible with modern P1]
and the P2 observable is left unchanged.
The biases vary from satellite to satellite but tend to be
relatively constant for long periods of time. Note that since the biases
change from satelite to satellite, they will not be eliminated by double
differencing.
A converter utility (cc2noncc.f) is available for analysts to use to
transform AOA TurboRogue, AOA ICS-4000Z, Trimble 4000, and similar RINEX
files. An output file will be created only when an input RINEX file
indicates that the receiver type is one of these types, so it is vital
that the RINEX headers be reliable. Note that this conversion should only
be applied to create intermediate files for analysis purposes and should
never be used for general distribution of RINEX files!
The cc2noncc utility can be invoked by:
cc2noncc [biasfile] [type]
where
Input RINEX file name (required)
Output RINEX file name (required)
[biasfile] this file of historic P1-C1 values (optional)
[type] force corrections to be applied for these two
types: (optional but [biasfile] must be given)
C1P2 = C1 and P2 both are to be changed
C1 = only C1 is to be changed
Only the most recent P1-C1 bias values are used when [biasfile] is not
provided. By supplying the external bias file, the appropriate bias values
for any epoch in the past may be used, not just the most recent set which
is the default. When run with no runstring parameters, help info is
returned.
*============================================================================
-cc2noncc/info
+cc2noncc/rcvr
*============================================================================
*
* Listed below are the receiver types that are recognized by cc2noncc and
* for which observables will be modified. The receiver type is read from
* the the RINEX headers and so must be reliable (unless the forcing option
* is exercised in the runstring parameters). Comment lines start with
* non-blank characters.
*
* Cross-correlation style receivers (both C1 and P2' are modified):
cc2noncc-type:C1P2
AOA ICS-4000Z
ROGUE SNR-
ROGUE SNR-12
ROGUE SNR-12 RM
ROGUE SNR-8
ROGUE SNR-800
ROGUE SNR-8000
ROGUE SNR-8100
ROGUE SNR-8C
SPP GEOTRACER100
TOPCON GP-DX1
TOPCON TT4000SSI
TRIMBLE 4000
TRIMBLE 4000SSE
TRIMBLE 4000SSI
TRIMBLE 4000SST
*
* Non-cross-correlator receivers reporting C1 instead of P1 (only C1 is
* modified):
cc2noncc-type:C1
ASHTECH PF500
IFEN SX_NSR_RT_400
LEICA CRS1000
LEICA GMX902
LEICA GMX902GG
LEICA GR10
LEICA GR25
LEICA GRX1200
LEICA GRX1200+GNSS
LEICA GRX1200GGPRO
LEICA GRX1200PRO
LEICA GX1230
LEICA GX1230+GNSS
LEICA GX1230GG
LEICA MC1000
LEICA MC500
LEICA RS500
LEICA SR399E
LEICA SR520
LEICA SR530
LEICA SR9500
LEICA SR9600
NOV 15A
NOV EURO4-1.00-222
NOV MILLEN-RT2
NOV MILLEN-STD
NOV MILLEN-STDW
NOV OEM4-G2
NOV OEMV1
NOV OEMV1G
NOV OEMV2
NOV OEMV3
NOV OEMV3-RT2
NOV WAASGII
TRIMBLE 4700
TRIMBLE 5700
TRIMBLE 7400MSI
TRIMBLE MS750
TRIMBLE NETR3
TRIMBLE NETR5
TRIMBLE NETR8
TRIMBLE NETR9
TRIMBLE NETRS
TRIMBLE R7
TRIMBLE R8
*
*============================================================================
-cc2noncc/rcvr
+cc2noncc/corr
*
* Below is the history of f(i) = i bias values adopted by the IGS.
* Note that the format is the same as the data statements in cc2noncc.f
* except that epoch lines are added ( h YYYY MM DD). Bias values for 40
* satellites are expected; missing values are flagged as -9.999d9. Comment
* lines start with non-blank characters.
*
* biases are always in units of ns and are listed in PRN order from
* PNR01 thru PRN40.
*
*----------------------------------------------------------------------------
* For data collected before 02 April 2000 -- no biases established
*
* During the period from June 1999 till April 2000, data from the relatively
* small number of non-cross-correlating receivers were converted to CC-style
* using the utility noncc2cc.
*
h 1980 01 01
data bias / -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9 /
*
*----------------------------------------------------------------------------
* For data collected starting 02 April 2000 -- IGS Mail #2744 (15 Mar 2000)
* (cc2noncc.f version 1.3, 09 Mar 2000 -- original units converted from
* meters to ns)
*
h 2000 04 02
data bias / -0.223d0, -1.027d0, 0.173d0, 1.528d0, -0.650d0,
+ 0.574d0, -0.987d0, -0.801d0, 0.390d0, -1.551d0,
+ -0.117d0, -9.999d9, 1.755d0, 0.574d0, -0.991d0,
+ -0.674d0, -0.887d0, 0.173d0, 0.233d0, -9.999d9,
+ -0.280d0, -1.564d0, -0.490d0, 0.440d0, 0.807d0,
+ 1.444d0, -0.023d0, -9.999d9, 0.987d0, 1.805d0,
+ -0.610d0, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9 /
*
* These values were determined by Ron Muellerschoen (JPL) based on 8 days
* of 1-s data from 14 Ashtech Z12 receivers kept in stable conditions.
* The raw data were collected between 3-Jan-2000 16:00 and 11-Jan-2000
* 21:00. These biases have been renormalized to zero mean across the
* constellation in order to leave the net receiver clock bias unchanged
* for the older receiver types.
*
*----------------------------------------------------------------------------
* For data collected starting 18 June 2000 -- IGS Mail #2879 (09 Jun 2000)
* (cc2noncc.f version 1.4, 08 Jun 2000 -- original units converted from
* meters to ns)
*
h 2000 06 18
data bias / -0.254d0, -0.871d0, 0.247d0, 1.695d0, -0.580d0,
+ 0.697d0, -0.907d0, -0.524d0, 0.414d0, -1.548d0,
+ -0.037d0, -9.999d9, 1.831d0, -9.999d9, -1.054d0,
+ -0.617d0, -0.761d0, 0.277d0, 0.270d0, -0.854d0,
+ -0.457d0, -1.501d0, -0.494d0, 0.600d0, 0.687d0,
+ 1.544d0, 0.013d0, -9.999d9, 0.937d0, 1.868d0,
+ -0.624d0, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9 /
*
* These values were determined by David Jefferson (JPL) based on Ashtech Z12
* data only (e-mail on 08 June 2000). The data were collected after the
* launch of PRN20/SVN51, which has been added, and the decommissioning of
* PRN14, which has been dropped. These biases have been renormalized to
* zero mean across the constellation in order to leave the net receiver
* clock bias unchanged for the older receiver types.
*
*----------------------------------------------------------------------------
* For data collected starting 14 January 2001 -- IGS Mail #3160 (05 Jan 2001)
* (cc2noncc.f version 2.0, 04 Jan 2001)
*
h 2001 01 14
data bias / 0.222d0, -0.546d0, 0.042d0, 1.294d0, -0.798d0,
+ 0.625d0, -0.523d0, -0.193d0, 0.048d0, -1.002d0,
+ -0.329d0, -9.999d9, 1.545d0, -0.409d0, -0.755d0,
+ -9.999d9, -0.522d0, -9.999d9, 0.582d0, -0.958d0,
+ -0.172d0, -1.374d0, -1.018d0, 0.459d0, 0.775d0,
+ 1.077d0, 0.213d0, -0.144d0, 0.611d0, 1.745d0,
+ -0.496d0, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9 /
*
* This set of biases was determined by Stefan Schaer (AIUB) as a byproduct
* of his ionosphere monitoring. They are direct estimates from a mixed
* network of cross-correlation style and non-cross-correlation receivers;
* see IGS Mail #2827 (09 May 2000) and the web site at
* http://www.aiub.unibe.ch/ionosphere.html .
* These values are a 7-day moving average of the daily estimates. The
* particular set used here were those posted on 26 Dec 2000.
* Note that new satellites PRN28 (Aug 2000) and PRN14 (Dec 2000) have been
* added and that PRN16 (Jul 2000) and PRN18 (Jun 2000) were decommissioned.
*
*----------------------------------------------------------------------------
* For data collected starting 18 March 2001 -- IGS Mail #3220 (05 Mar 2001)
* (cc2noncc.f version 2.1, 05 Mar 2001)
*
h 2001 03 18
data bias / 0.039d0, -0.469d0, 0.104d0, 1.655d0, -0.634d0,
+ 0.681d0, -0.192d0, -0.309d0, 0.317d0, -1.003d0,
+ -0.161d0, -9.999d9, 1.376d0, -0.391d0, -0.238d0,
+ -9.999d9, -0.695d0, -0.242d0, 0.541d0, -1.114d0,
+ -0.176d0, -1.664d0, -1.033d0, 0.708d0, 0.373d0,
+ 1.022d0, 0.123d0, -0.323d0, 0.511d0, 1.621d0,
+ -0.426d0, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9 /
*
* This set of biases was determined by Stefan Schaer (AIUB) as a byproduct
* of his ionosphere monitoring; see above. These values are the monthly
* averages of the daily estimates for February 2001 posted on 05 March 2001.
* Note that new satellite PRN18 has been added.
*
*----------------------------------------------------------------------------
* For data collected starting 20 January 2002 -- IGS Mail #3674 (08 Jan 2002)
* (cc2noncc.f version 2.4, 02 Jan 2002)
*
h 2002 01 20
data bias / 0.377d0, -0.611d0, 0.343d0, 1.109d0, -0.738d0,
+ 0.329d0, -0.557d0, -0.061d0, 0.172d0, -1.226d0,
+ 0.229d0, -9.999d9, 1.519d0, -0.279d0, -0.751d0,
+ -9.999d9, -0.722d0, -0.666d0, -9.999d9, -0.953d0,
+ -0.088d0, -0.626d0, -1.308d0, 0.167d0, 0.791d0,
+ 0.888d0, 0.367d0, -0.217d0, 0.760d0, 2.015d0,
+ -0.261d0, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9 /
*
* This set of biases was determined by Stefan Schaer (AIUB) as a byproduct
* of his ionosphere monitoring; see above. These values are the monthly
* averages of the daily estimates for November 2001 posted on 05 December
* 2001. Note that PRN19 was decommissioned on 11 Sept 2001.
*
*----------------------------------------------------------------------------
* For data collected starting 02 March 2003 -- IGS Mail #4279 (26 Feb 2003)
* (cc2noncc.f version 4.0, 26 Feb 2003)
*
h 2003 03 02
data bias / -0.067d0, -0.944d0, 0.106d0, 1.508d0, -0.802d0,
+ 0.645d0, -0.916d0, -0.514d0, 0.380d0, -1.480d0,
+ 0.692d0, -9.999d9, 1.503d0, 0.289d0, -0.830d0,
+ -0.561d0, -0.595d0, 0.084d0, -9.999d9, -1.084d0,
+ -9.999d9, -1.609d0, -0.740d0, 0.347d0, 0.720d0,
+ 1.223d0, -0.023d0, -0.113d0, 0.867d0, 2.211d0,
+ -0.296d0, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9 /
*
* This set of biases was determined by Stefan Schaer (AIUB) as a byproduct
* of his ionosphere monitoring; see above. These values are the 30-day
* averages of the daily estimates for the period ending 21 Feb 2003
* (retrieved 26 Feb 2003). Note the constellation has changed with the
* addition of PRN16 and the decommissioning of PRN21.
*----------------------------------------------------------------------------
* For data collected starting 18 May 2003 -- IGS Mail #4366 (06 May 2003)
* (cc2noncc.f version 4.3, 05 May 2003)
*
h 2003 05 18
data bias / -0.107d0, -1.062d0, 0.149d0, 1.535d0, -0.890d0,
+ 0.596d0, -0.618d0, -0.513d0, 0.320d0, -1.658d0,
+ 0.755d0, -9.999d9, 1.559d0, 0.427d0, -0.947d0,
+ -0.285d0, -0.858d0, 0.085d0, -9.999d9, -1.019d0,
+ -0.267d0, -1.422d0, -0.745d0, 0.345d0, 0.611d0,
+ 1.322d0, 0.005d0, -0.096d0, 0.956d0, 2.065d0,
+ -0.244d0, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9 /
*
* This set of biases was determined by Stefan Schaer (AIUB) as a byproduct
* of his ionosphere monitoring; see above. These values are the monthly
* averages of the daily estimates for April 2003 (generated 04 May 2003).
* Note that since the last update the constellation has changed with the
* addition of a new PRN21. Also, values have changed significantly for
* PRN07, PRN10, PRN16 (new last update), PRN17, and PRN22.
*----------------------------------------------------------------------------
* For data collected starting 04 Feb 2004 -- IGS Mail #4825 (04 Feb 2004)
* (cc2noncc.f version 4.5, 04 Feb 2004)
*
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 /
*
* This set of biases was determined by Stefan Schaer (AIUB) as a byproduct
* of his ionosphere monitoring; see above. These values are the monthly
* averages of the daily estimates for January 2004 (generated 04 Feb 2004).
* 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. Besides the large
* bias change for PRN22, PRN07 and PRN23 are the only others having bias
* changes greater than 0.3 ns.
*----------------------------------------------------------------------------
* For data collected starting 16 May 2004 -- IGS Mail #4937 (10 May 2004)
* (cc2noncc.f version 4.6, 10 May 2004)
*
h 2004 05 16
data bias / -0.076d0, -9.999d9, 0.014d0, 1.473d0, -0.872d0,
+ 0.565d0, -0.809d0, -0.563d0, 0.327d0, -1.579d0,
+ 0.609d0, -9.999d9, 1.600d0, 0.311d0, -1.040d0,
+ -0.460d0, -0.915d0, 0.014d0, -2.410d0, -1.084d0,
+ -0.298d0, 0.652d0, -9.999d9, 0.258d0, 0.552d0,
+ 1.247d0, -0.020d0, -0.162d0, 0.949d0, 2.082d0,
+ -0.366d0, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9 /
*
* This set of biases was determined by Stefan Schaer (AIUB) as a byproduct
* of his ionosphere monitoring; see above. These values are the monthly
* averages of the daily estimates for April 2004 (generated 04 May 2004).
* Note that since the last update the constellation has changed with the
* decommissioning of the old PRN23 on 13 Feb 2004, the end of life of
* PRN02 on 23 Feb 2004 (though not officially decommissioned yet), and
* the new IIR-11 satellite (PRN19) launched on 20 Mar 2004. Besides the
* bias changes for PRN02, PRN19, and PRN23, the only other having a bias
* change greater than 0.2 ns was PRN22, which became operational in late
* Dec 2003.
*----------------------------------------------------------------------------
* For data collected starting 15 Aug 2004 -- IGS Mail #4987 (04 Aug 2004)
* (cc2noncc.f version 4.7, 04 Aug 2004)
*
h 2004 08 15
data bias / -0.053d0, -9.999d9, -0.011d0, 1.450d0, -0.944d0,
+ 0.538d0, -1.228d0, -0.243d0, 0.401d0, -1.582d0,
+ 0.553d0, -9.999d9, 1.621d0, 0.441d0, -0.948d0,
+ -0.410d0, -0.835d0, 0.063d0, -2.323d0, -1.074d0,
+ -0.345d0, 0.605d0, -0.225d0, 0.289d0, 0.570d0,
+ 1.277d0, 0.001d0, -0.204d0, 0.969d0, 2.095d0,
+ -0.449d0, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9 /
*
* This set of biases was determined by Stefan Schaer (AIUB) as a byproduct
* of his ionosphere monitoring; see above. These values are the monthly
* averages of the daily estimates for July 2004 (generated 04 Aug 2004).
* Note that since the last update the constellation has changed with the
* launch of a new IIR-12 satellite (SVN60/PRN23) on 23 Jun 2004. Besides
* the bias change for PRN23, the only others changing by more than 0.2 ns
* were PRN07 (-0.42 ns) and PRN08 (+0.32 ns).
*----------------------------------------------------------------------------
* For data collected starting 16 Jan 2005 -- IGS Mail #5078 (04 Jan 2005)
* (cc2noncc.f version 4.8, 04 Jan 2005)
h 2005 01 16
data bias / -0.028d0, -0.061d0, 0.077d0, 1.334d0, -0.929d0,
+ 0.664d0, -0.912d0, -0.335d0, 0.529d0, -1.567d0,
+ 0.535d0, -9.999d9, 1.541d0, 0.335d0, -1.057d0,
+ -0.419d0, -0.906d0, 0.098d0, -2.269d0, -1.105d0,
+ -0.346d0, 0.579d0, -0.221d0, 0.152d0, 0.735d0,
+ 1.247d0, -0.018d0, -0.205d0, 0.842d0, 2.017d0,
+ -0.307d0, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9 /
* This set of biases was determined by Stefan Schaer (AIUB) as a byproduct
* of his ionosphere monitoring; see above. These values are the monthly
* averages of the daily estimates for December 2004 (generated 04 Jan 2005).
* Note that since the last update the constellation has changed with the
* launch of a new IIR-13 satellite (SVN61/PRN02) on 06 Nov 2004. Besides
* the new bias for PRN02, which is close to zero, the only other having a
* bias change greater than 0.2 ns is PRN07 (+0.32ns), which has historically
* been unstable.
*----------------------------------------------------------------------------
* For data collected starting 03 Oct 2005 -- IGS Mail #5260 (23 Nov 2005)
* (cc2noncc.f version 5.0, 23 Nov 2005)
h 2005 10 03
data bias / -0.233d0, -0.033d0, -0.163d0, 1.234d0, -0.944d0,
+ 0.444d0, -1.132d0, -0.416d0, 0.366d0, -1.651d0,
+ 0.591d0, -9.999d9, 1.529d0, 0.108d0, -1.326d0,
+ -0.525d0, 1.391d0, -0.012d0, -2.026d0, -1.228d0,
+ -0.392d0, 0.532d0, 0.130d0, -0.069d0, 0.575d0,
+ 1.083d0, -0.189d0, -0.232d0, 0.643d0, 2.016d0,
+ -0.073d0, -9.999d9, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9 /
* This set of biases was determined by Stefan Schaer (AIUB) as a byproduct
* of his ionosphere monitoring; see above. These values are the 30-day
* averages of the daily estimates ending on 19 Nov 2005. Note that since
* the last update in Jan 2005 the constellation has changed with the launch
* of the new IIR-M1 satellite (SVN53/PRN17) on 26 Sep 2005 and the
* decommissioning of SVN31/PRN31 on 25 Oct 2005. Besides the new bias for
* PRN17 the only other having a bias change greater than 0.3 ns is PRN23
* (+0.35ns).
*----------------------------------------------------------------------------
* For data collected starting 01 Oct 2007 -- IGS Mail #5662 (22 Nov 2007)
* CODE'S MONTHLY GPS P1-C1 DCB SOLUTION, YEAR-MONTH 07-10
* ftp://ftp.aiub.unibe.ch/CODE/2007/P1C10710.DCB.Z
* ftp://ftp.aiub.unibe.ch/CODE/2007/P1C10710.F.Z
h 2007 10 01
data bias / -0.532d0, -0.076d0, -0.580d0, 1.059d0, -1.319d0,
+ 0.132d0, -1.664d0, -0.627d0, 0.034d0, -1.950d0,
+ 0.508d0, 1.391d0, 1.389d0, 0.013d0, 1.792d0,
+ -0.818d0, 1.251d0, -0.472d0, -2.090d0, -1.430d0,
+ -0.527d0, 0.514d0, 0.648d0, -0.337d0, 0.355d0,
+ 0.870d0, -0.496d0, -0.388d0, 0.348d0, 1.815d0,
+ 1.629d0, -0.443d0, -9.999d9, -9.999d9, -9.999d9,
+ -9.999d9, -9.999d9, -9.999d9, -9.999d9, -9.999d9 /
* This set of biases was determined at CODE (AIUB) as a by-product of the
* GNSS ionosphere/clock analysis; see above. These values are the monthly
* averages of the daily estimates for October 2007 (generated 04 Nov 2007).
* Note that since the last update the constellation has changed with:
* - PRN12/SVN58 launched on 11 Nov 2006
* - PRN15/SVN55 launched on 17 Oct 2007 (as replacement for PRN15/SVN15)
* - PRN31/SVN52 launched on 25 Sep 2006 (as replacement for PRN31/SVN31)
* - PRN32/SVN23 re-activated on 02 Dec 2006 (originally assigned to PRN23)
* Besides the resulting bias changes for PRN12 (+1.39 ns), PRN15 (+3.12 ns),
* PRN31 (+1.70 ns), PRN32 (-0.44 ns), PRN03 and PRN23 are the only others
* having bias changes greater than 0.5 ns (with -0.53 ns and +0.52 ns).
*----------------------------------------------------------------------------
-cc2noncc/corr