Bernese GPS Software Version 5.0 - Bernese GNSS Software

16. Antenna Phase Center Offsets and Variations
Figure 16.5: Program input panels for the GNSS antenna offset determination in program
GPSEST.
must be processed together in one GPSEST run or the individual solutions of the different
sessions have to be externally combined. In both cases, the receiver antenna offsets and the
azimuth and elevation dependent variations, the program output of GPSEST contains only
the estimated corrections w.r.t. the introduced a priori model.
The results of the receiver antenna model estimation may be stored in files specified in
panel “GPSEST 2.2: Output Files 2”. Please note, that they are written into the campaign
directory (default:OUT) whereas the input antenna phase center eccentricities are introduced
from files located in ${X}/GEN. Furthermore it has to be noted that the introduced and
estimated elevation and azimuth dependent part of the antenna phase center variations
need to be equal in terms of resolution. The only exception is that from an introduced
spherical harmonic model any piece-wise linear model can be extracted.
16.4.2 Estimation of Satellite Antenna Model Parameters
In contrast to the estimation of receiver antenna phase center corrections the generation of
satellite antenna model parameters requires a global network. Precise station coordinates
and satellite orbits are requested, too. Long time series of data should preferably be analyzed
to obtain reliable results. Please note, that uncertainties of the introduced receiver antenna
model may map into the satellite antenna model. We refer to [Schmid and Rothacher, 2003]
for more details on the estimation of satellite antenna model parameters.
Due to high correlation, satellite antenna offsets and phase center variations can not be
estimated together in one processing step. First estimate the satellite antenna phase center
variations. A zero mean condition is imposed on all grid points. Even if a corresponding
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