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Bernese GPS Software Version 5.0 - Bernese GNSS Software

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22. Data Structure<br />

22.4.4 Antenna Phase Center Offsets and Patterns<br />

Type: ASCII<br />

Directory: ${X}/GEN (UNIX) or %X%\GEN (Windows) for the input file, campaignspecific<br />

directory OUT for output files.<br />

Extension: Variable.<br />

Content: Antenna phase center offsets and variations for receiver and satellite antennas.<br />

Created by: User-defined for input, <strong>GPS</strong>EST (”Menu>Processing>Parameter estimation”) for estimation,<br />

PHCCNV (”Menu>Conversion>ANTEX to <strong>Bernese</strong> format”) for output. Available<br />

from BSW aftp server.<br />

Used by: All programs processing <strong>GNSS</strong> observations.<br />

Example: Figures 22.5 and 22.6 show an example using format 2 (formats are explained<br />

at the bottom of Figure 22.5). An update version of the file PHAS COD.I05 is<br />

available at the anonymous BSW ftp area (see Section 4.12).<br />

Remarks:<br />

• Use IGS values in order to assure consistency with the IGS products.<br />

• Values may be imported from ANTEX using PHCCNV (”Menu>Conversion>ANTEX to <strong>Bernese</strong><br />

format”).<br />

• Elevation-dependent antenna phase center corrections are of importance for the combination<br />

of different antenna pairs in a network. Between Trimble and Dorne Margolin<br />

antennas the effect of non-modeled elevation-dependent variations may reach more<br />

than 10 cm in station height [Rothacher et al., 1996]. At present (January 2007) the<br />

recommended values to be used in the processing is the absolute model IGS05. These<br />

values were obtained from robot calibrations.<br />

• The <strong>Bernese</strong> PCV file contains patterns for the <strong>GNSS</strong> satellites (which are zero for<br />

relative phase patterns). The patterns have to be named with the sensor name that is<br />

specified in the second section in the satellite information file (see Section 22.4.5), e.g.,<br />

MW TRANSM IIA 032 for the Block IIA satellite with PRN 1. Satellite patterns,<br />

even if zero, have to be present in the file for <strong>Version</strong> <strong>5.0</strong> .<br />

• The IGS has investigated the effect of using absolute antenna phase patterns. For<br />

large networks such patterns require the use of block-specific satellite antenna phase<br />

patterns and satellite specific antenna offsets [Schmid and Rothacher, 2003]. Starting<br />

from <strong>GPS</strong> week 1400 the IGS has switched to the absolute antenna model IGS05.<br />

• Starting from <strong>GPS</strong> week 1017 (July 1999), a new IGS naming convention for receiver<br />

and antenna names was introduced. A list of the currently valid receiver and antenna<br />

names may be found at ftp://ftp.igs.org/igscb/station/general/.<br />

• It is possible to define different phase center locations for each individual antenna by<br />

using antenna numbers in the observation files.<br />

• Note the different formats: “0” means no elevation dependent corrections, “1” means<br />

elevation dependent values given to the right of the offset values, and “2” means<br />

phase center maps (grid) or spherical harmonics available. An example of elevationand<br />

azimuth-dependent grid information is shown in Figure 22.6.<br />

• The order of the antennas in the first part and in the second part have to be the same.<br />

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