Bernese GPS Software Version 5.0 - Bernese GNSS Software

6.2.5 Resulting Smoothed RINEX Files
6.2 Preprocessing on the RINEX Level
The limitations of the RNXSMT are due to the use of code observations which implies that
small outliers in the phase cannot be detected safely. With a typical RMS of 0.5 cycles for
the Melbourne-Wübbena combination the 4σ outlier detection level is about 160 cm. All
carrier phase outliers below this level will not be detected. They will have to be detected by
screening the post-fit residuals after a first parameter estimation step (see Section 6.6.2).
The code observations from different receiver types may have a significantly different noise
such that a station specific weighting of the observations usually becomes necessary. Because
the smoothed code is derived from the phase measurements it is much more homogeneous
and a station specific weighting of the code data is not necessary. The smoothed code
observations may be introduced for ambiguity resolution using the Melbourne-Wübbena
linear combination because they do not contain big outliers anymore.
One big advantage of the program RNXSMT is its complete independence on the satellite
orbits and the position and velocity of the receiver. This means that this data cleaning
method can also be used for kinematic applications and even for very fast moving object,
e.g., Low Earth Orbiting satellites (LEOs). The only condition is the availability of dual
frequency data for code and phase.
RNXSMT sets the signal-to-noise ratio for bad observations to 1 and it sets cycle slip flags at
those epochs where a cycle slip was detected. If you disable the option “Flag bad phase observations”
in panel “RNXSMT 2.3: Options” the signal to noise ratio for bad phase observations
Figure 6.4: “SIGNAL STRENGTH REQUIREMENTS” in RXOBV3 to import smoothed RINEX
files into Bernese formatted observation files.
Bernese GPS Software Version 5.0 Page 107