Bernese GPS Software Version 5.0 - Bernese GNSS Software

10. Station Coordinates and Velocities
On the other hand the disregard of correlations may also be a desired feature. Errors introduced
by a misbehaving station are not disseminated throughout the whole network but
only influence the results of that specific stations. Thus the PPP is well apt to identify
station problems.
To run GPSEST in PPP mode some options need special attendance. The zero-difference
mode must be activated in panel “GPSEST 1.1: Input Files 1”, the estimation of satellite clock
corrections must be switched off (option “GNSS clock offsets” in panel “GPSEST 5.1: Setup of
Parameters and Pre-Elimination 1”), and receiver clock corrections must set up (“Receiver clock
offsets”). Due to the possibly large number of receiver clock offsets it might be necessary
to pre-eliminate them EVERY EPOCH. Finally, the datum definition should be set to “Free
network solution” in panel “GPSEST 4: Datum Definition for Station Coordinates”.
If no parameters common to several stations are set up (e.g., geocenter coordinates) there is
no advantage in processing several stations in one program run compared to one individual
run per station. Otherwise it is still possible to process single stations in separate runs if
normal equations are stored. They may subsequently be combined with ADDNEQ2.
Please note, that code observations from GLONASS can not be used for PPP in Bernese
GPS Software, Version 5.0 . The corresponding frequency dependent receiver biases are not
considered in the processing, yet.
One of the example BPEs provided with the software distribution shows a possible implementation
of a PPP procedure. It is described in Section 20.4.1.
10.6 Coordinate and Velocity Related Auxiliary Programs
The Bernese GPS Software provides several programs dealing with coordinate and velocity
files. Typical applications are, e.g., Helmert transformations, comparison of several coordinate
files, velocity computation based on a model, etc. All coordinate/velocity tools can
be found at ”Menu>Service>Coordinate tools”. The most common programs are subsequently described.
10.6.1 Extracting Coordinates/Velocities from SINEX
Although program SNX2NQ0 (”Menu>Conversion>SINEX to normal equations”) is not directly coordinate
related it should be mentioned here. Apart from the conversion of SINEX files to
Bernese normal equation files it allows to extract station coordinates and velocities from
the SINEX file. This may be used in conjunction with the official ITRF SINEX file to get
a complete set of ITRF station coordinates and velocities. The program is described in
Section 4.6.2.
10.6.2 Helmert Transformation
Program HELMR1 (”Menu>Service>Coordinate tools>Helmert transformation”) allows to compare two
coordinate sets after estimating up to seven transformation parameters of a Helmert or
similarity transformation (three translations, three rotations, and a scaling factor).
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