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Bernese GPS Software Version 5.0 - Bernese GNSS Software

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20.5 Processing own Data With Example BPEs<br />

Note that in the example, we use the campaign directories as location for the input files.<br />

Instead of "$dirPre" you should type in the location of the precise orbit files in your<br />

local data pool. If necessary you may also change the filename – use time variable to keep<br />

the script session independent (see Sections 18.5.1 and 19.6). The ORX directory contains<br />

in this example the original RINEX observation files. This ensures, that you will always<br />

have a copy of these files available (keywords: RINEX screening, cleaning up scripts). After<br />

these preparatory steps, you are ready to run a PCF from the examples with your own<br />

campaign/data. Furthermore, you could also adapt the save and deletion scripts to your<br />

preferences. It’s as simple as that.<br />

You may need more changes in program options or user scripts depending on your application<br />

(e.g., another troposphere setup according to the recommendations in Section 11.6 if<br />

you analyze a local instead of regional network). Be sure to keep the program input panels<br />

in the OPT directories consistent with your changes! Surely, by now, you also have realized<br />

the value of using menu or BPE variables as much as possible to keep modifications in<br />

scripts and panels simple.<br />

If you have changed some of the user scripts or program input options and you want to<br />

go back to the original examples you can copy them from the ${X}/PCF, ${X}/OPT, and<br />

${X}/USERSCPT into your user environment ${U}/PCF, ${U}/OPT, and ${U}/SCRIPT.<br />

20.5.2 <strong>GNSS</strong> Processing<br />

The double-difference example is designed for the analysis of <strong>GNSS</strong> data (<strong>GPS</strong> and<br />

GLONASS). If you carefully check the results, you will see that in the initial setup of<br />

the example only <strong>GPS</strong> data are used. The reason is, that IGS precise files contain only <strong>GPS</strong><br />

orbit information.<br />

If you have data files from combined receivers you can use the orbits and Earth orientation<br />

parameters from CODE containing consistent <strong>GPS</strong> and GLONASS orbits. To implement<br />

this you have to change the filename for the orbit and pole files in the R2S COP script<br />

from $filDat = "IGS${wwwwd}.PRE"; to $filDat = "COD${wwwwd}.PRE"; and<br />

from $filDat = "IGS${wwww}7.IEP"; to $filDat = "COD${wwww}7.IEP";<br />

You may change the content of the BPE variable V B to indicate the use of CODE orbits in<br />

filenames.<br />

Alternativly you have to merge the combined <strong>GPS</strong> and GLONASS final orbit files from<br />

the IGS. They are not as consistent as the CODE product because they are (apart from<br />

the CODE contribution) generated in individual procedures by a different set of analysis<br />

centers which are futhermore combined in two independent procedures.<br />

20.5.3 Change of the Reference Frame<br />

The examples use the IGS00 realization of the ITRF2000 reference frame. The IGS realization<br />

has been updated to IGS00b and is used since <strong>GPS</strong>-week 1253 (January, 2004;<br />

IGS Mail 4666). To change this reference frame, you have to download the corresponding<br />

files from http://www.aiub.unibe.ch/download/BSWUSER50/STA: IGS 00B R.CRD,<br />

IGS 00B R.VEL, andIGS 00B.FIX. You can generate a new a priori coordinate set by running<br />

the PPP example using IGS 00B R for the “Master/reference CRD/VEL file name” (V CRDREF)<br />

<strong>Bernese</strong> <strong>GPS</strong> <strong>Software</strong> <strong>Version</strong> <strong>5.0</strong> Page 457

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