Bernese GPS Software Version 5.0 - Bernese GNSS Software

12. Ionosphere Modeling and Estimation
You might set up in addition single-layer height parameters as unknowns in panel
“GPSEST 6.4.1: Global Ionosphere Parameters 1”. In that case, GPSEST requires an a priori
GIM file – stemming from an initial program run – to be specified in panel “GPSEST 1.1:
Input Files 1”, option “Ionosphere models”, because the parameter estimation problem is no
longer linear.
Deterministic ionosphere models in a piece-wise linear representation may be stored just
like other parameters in normal equation files in the program GPSEST. They may be combined
later on in program ADDNEQ2 (”Menu>Processing>Normal equation stacking”). Absolute and
relative constraints may be specified in panel “ADDNEQ2 9: Options for Atmospheric Parameters”.
Just like GPSEST, ADDNEQ2 offers the possibility to store IONEX as well as Bernese
ionosphere result files. All parameter operations described in Section 9.3 may be applied to
ionosphere parameters, too. Due to the piece-wise linear representation ionosphere models
of consecutive days will automatically result in a continuous model. To reduce the number
of parameters in, e.g., a three-day solution the EXCEPT FOR BOUNDARY pre-elimination option
for the first and third day may be applied. As demonstrated in the provided PPP.PCF
example (description in Section 20.4.1) ADDNEQ2 may also be used to compute a regional
ionosphere model from a set of subnetworks or even from a set of individually analyzed
stations.
CODE’S GLOBAL IONOSPHERE MAPS FOR DAY 139, 2003 24-MAY-03 12:43
--------------------------------------------------------------------------------
MODEL NUMBER / STATION NAME : 1390-01
MODEL TYPE (1=LOCAL,2=GLOBAL,3=STATION) : 2
MAXIMUM DEGREE OF SPHERICAL HARMONICS : 15
MAXIMUM ORDER : 15
DEVELOPMENT WITH RESPECT TO
GEOGRAPHICAL (=1) OR GEOMAGNETIC (=2) FRAME : 2
MEAN (=1) OR TRUE (=2) POSITION OF THE SUN : 1
MAPPING FUNCTION (0=NONE,1=COSZ,2=MSLM,3=ESM) : 2
HEIGHT OF SINGLE LAYER AND ITS RMS ERROR (KM) : 450.00 0.00
COORDINATES OF EARTH-CENTERED DIPOLE AXIS
LATITUDE OF NORTH GEOMAGNETIC POLE (DEGREES) : 79.59
EAST LONGITUDE (DEGREES) : -71.99
PERIOD OF VALIDITY
FROM EPOCH / REFERENCE EPOCH (Y,M,D,H,M,S) : 2003 05 19 00 00 00
TO EPOCH :
LATITUDE BAND COVERED
MINIMUM LATITUDE (DEGREES) : -88.62
MAXIMUM LATITUDE (DEGREES) : 89.57
ADDITIONAL INFORMATION
NUMBER OF CONTRIBUTING STATIONS : 178
NUMBER OF CONTRIBUTING SATELLITES : 38
ELEVATION CUT-OFF ANGLE (DEGREES) : 10
MAXIMUM TEC AND ITS RMS ERROR (TECU) : 65.25 0.68
COMMENT / WARNING :
COEFFICIENTS
DEGREE ORDER VALUE (TECU) RMS (TECU)
0 0 23.21633875 0.0333
1 0 5.64451669 0.0303
1 1 8.01834535 0.0334
...
15 -14 0.01665035 0.0235
15 15 0.00388322 0.0249
15 -15 0.02498974 0.0248
...
Figure 12.17: Example for an ionosphere file containing a series of global TEC models.
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