Bernese GPS Software Version 5.0 - Bernese GNSS Software

20.4.2 Double-Difference Processing Example (RNX2SNX.PCF)
20.4 Description of the Processing Examples
The RNX2SNX.PCF is intended for a double-difference based analysis of RINEX GNSS observation
data from a regional network. Station coordinates and troposphere parameters
are estimated and stored in Bernese and SINEX format to facilitate further processing and
combination. For each session, the corresponding normal equation information is saved for
a subsequent multi-session solution (allowing the estimation of station velocities).
Some important features of this BPE are:
• Observation files with significant gaps or unexpectedly big residuals will automatically
be removed from the processing to ensure a robust processing and a reasonable network
solution.
• Phase ambiguity fixing is attempted for baselines up to 2000 km length based on
the quasi-ionosphere-free (QIF) resolution strategy. Ambiguity resolution is only performed
for GPS observations.
• The final network solution is a minimum constraint solution, realized by three no-nettranslation
conditions imposed on a set of ITRF2000 (more precisely IGS00) reference
coordinates. The coordinates of all involved fiducial stations are subsequently verified
by means of a 3-parameter Helmert transformation. In case of discrepancies, the network
solution is recomputed based on a reduced set of fiducial stations.
• Resulting SINEX data should allow for both reconstruction of the unconstrained,
free network solution and for straightforward extraction of station coordinates of the
originally computed minimum-constraint solution.
Besides some standard files (orbit and pole information, etc.), four files are specifically
required to execute this PCF:
(1) station name abbreviation file (EXAMPLE.ABB),
(2) coordinate file (IGS 00.CRD),
(3) velocity file (IGS 00.VEL), and
(4) list of reference sites in the coordinate file (IGS 00.FIX).
The use of the example PPP.PCF to create three of these files is explicitly foreseen. The
main purpose of that preparatory BPE processing step is the computation of approximate
station coordinates for all new points of the GNSS network to be analyzed. That processing
step includes creation of a complete coordinate file. The fourth file listing the reference sites
must be generated manually.
Note when processing your own data: All stations to be processed must be included in the
coordinate, velocity, and station name abbreviation files. At least two or three reference
sites should be included in the solution.
The next sections provide details of each PCF step in textual structured blocks.
Bernese GPS Software Version 5.0 Page 437