Bernese GPS Software Version 5.0 - Bernese GNSS Software

9. Combination of Solutions
(2) Transfer the ASCII normal equation files to the new platform.
(3) Convert the normal equation files from ASCII to (old format) binary files using
NEQFMT from Version 5.0 .
(4) Convert the old binary normal equation files to new format normal equation files using
NEQ2NQ0.
9.5 Typical Applications
ADDNEQ2 allows for a large variety of applications. Obvious examples are the combination
of final results for larger campaigns, the combination and densification of networks.
Similarly ADDNEQ2 may be used to combine the results from short sessions, e.g., from
hourly processing steps. In Chapter 10 more information is provided on the application of
ADDNEQ2 for datum definition and estimation of station velocities. Chapter 15 informs on
how to use ADDNEQ2 to perform long-arc orbit analysis.
ADDNEQ2 may also be used to generate a multitude of different solutions for scientific
investigations, all based on the same GPSEST run. You may, e.g., use GPSEST to compute
a solution with hourly or sub-hourly resolution of troposphere parameters and setting up
tropospheric gradient parameters. In a number of much shorter runs you may then with
ADDNEQ2 compute solutions with no gradient parameters (delete parameters) and/or with
reduced resolution of troposphere parameters. In this way you get very quickly a series
of different solutions and may, e.g., study the repeatability of station coordinates for the
different solutions. Similarly you may routinely set up, e.g., satellite antenna phase center
offset parameters and delete them in a second ADDNEQ2 run for your official solution. Using
the same normal equations you may then recover the phase center offsets and investigate
their effect on the solution.
This section gives some additional examples for applications. Users are invited to invent
many more applications fitting their particular needs or interests.
9.5.1 Cluster Combination
If large networks are analyzed the number of stations may no longer allow to process all
of them in a single GPSEST run with correct correlations. If the number of stations is
much larger than 30 the processing time and memory consumption may become very large.
A solution out of this situation is to analyze groups of baselines – so-called clusters –
independently with GPSEST and combine the cluster results using ADDNEQ2.
Correct correlations can be enabled in the individual GPSEST runs. Datum definition or
constraining of parameters can be kept simple as datum and constraints will be redefined
in the subsequent ADDNEQ2 run. All station coordinates may, e.g., be constrained as long
as the a priori coordinates are reasonably good. The only output, apart from the program
output file, is a cluster normal equation file. These normal equations are combined with
ADDNEQ2 to get the final solution. All result files, coordinate output file, troposphere
output file, etc., are generated in this run.
This strategy allows to partially consider the correlations between baselines, namely those
within each cluster. Correlations between baselines in different clusters are, however, lost
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