Bernese GPS Software Version 5.0 - Bernese GNSS Software

10. Station Coordinates and Velocities
It is recommended to be as restrictive as possible in eliminating observations during preprocessing.
The goal is to get as many epochs with reliable kinematic coordinate estimates
as possible. On the other hand, the low redundancy makes it difficult to detect bad observations.
The results are very sensitive to data quality. This makes it difficult to give a
ready-to-use recipe for a robust analysis of data from all types of kinematic stations.
In general, the best way is to follow the static procedure: Start with a precise point positioning
(see Section 10.5) to get a first solution for kinematic stations. Use these kinematic
(PPP-) positions as a priori values for the preprocessing of baselines. Sections 6.3.3 and
6.5.5 provide information on important issues concerning preprocessing of kinematic station
data. Algorithms for resolution of phase ambiguities to integer values can be applied
as described in Chapter 8 also for baselines containing kinematic stations.
If you have only short pieces of connected phase observations after preprocessing, you may
find jumps in the resulting time series (especially in the vertical component) at those epochs
where the phase ambiguities to all satellites are disconnected. This effect results from the
correlation between the phase ambiguity parameters and the vertical component of the
kinematic coordinates. It depends on the selected elevation cutoff and on the change of the
satellite configuration during the time interval that is connected by phase ambiguities.
To improve the situation first review the option settings for the “CYCLE SLIP DETECTION”,
“OUTLIER REJECTION”, and “SET UP MULTIPLE AMBIGUITIES” in program MAUPRP to check
whether they are appropriate to the quality of your data. You may then add the code data
to the analysis to stabilize the solution. For technical reasons, this is currently only possible
when analyzing the data in zero-difference mode.
If you are interested in the subdaily movement of a static station (e.g., changes in antenna
position due to an earthquake) you can follow static processing strategies. Only in the final
run of GPSEST – after the ambiguity resolution – you enable the kinematic positioning for
this station.
To demonstrate the performance of the Bernese GPS Software for such an application
we refer to Figure 10.5. It shows the results from a kinematic double-difference network
solution (ambiguities are introduced as integers) with a sampling of 30 seconds for the
IGS station NTUS (Singapore) during the earthquake in the Indian Ocean on March 28,
2005 at 16:09 UT. The effect of the quake on the GPS antenna’s position is delayed by
about 4 minutes. With a distance of about 750 km from the epicenter, this corresponds to
a propagation speed of the shock waves of about 3 km/s.
10.4.2 Kinematic Positioning in GPSEST
To enable the estimation of kinematic coordinates in GPSEST simply check the option “Kinematic
coordinates” in section “EPOCH PARAMETERS” of panel “GPSEST 5.1: Setup of Parameters
and Pre-Elimination 1”. An additional panel “GPSEST 6.5: Kinematic Coordinates” then allows
you to select the stations for which kinematic coordinates are requested. The selection of
stations for the kinematic positioning is independent from the station selection for the datum
definition. Kinematic positions are estimated even if the station was fixed for datum
definition.
As a priori coordinates for kinematic stations one may either use
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