Bernese GPS Software Version 5.0 - Bernese GNSS Software

4. Import and Export of External File Formats
4.5 IGS and IERS Pole Files
4.5.1 Definition
The pole files contain time series of pole coordinates, length of day, etc. necessary to perform
the transformation between the terrestrial and the celestial (inertial) reference frame. This
information is exchanged using a large variety of file formats. Within the IGS the IGS pole
file format version 2 is used. The format description can be found at
ftp://ftp.igs.org/igscb/data/format/erp.txt.
Figure 4.8 shows an example for an IGS formatted pole file generated at CODE.
Other EOP series may be obtained via anonymous ftp, too. These are in particular the IERS
C04 EOP series and the IERS Bulletin A and B series. Data files concerning Earth rotation
(C04 series, IERS Bulletin B) and celestial frame are stored at the IERS Central Bureau
and may be downloaded at http://hpiers.obspm.fr/eop-pc. These EOP time series are
the product of a combined analysis of the different space-geodetic techniques (VLBI, GPS,
SLR, DORIS). The IERS C04 time series provides slightly smoothed pole information at
daily intervals two times per week. Quick-look EOP series (IERS Bulletin A, containing
also predicted values) can be obtained from ftp://maia.usno.navy.mil/ser7.
Information concerning updates of internet addresses and server names is always provided by
the most recent IERS Annual Report. IERS pole files already transformed into the Bernese
format may be downloaded via anonymous ftp, too. They are located in the directory http:
//www.aiub.unibe.ch/download/BSWUSER50/ORB/ (files C04 yyyy.ERP, BULLET A.ERP).
4.5.2 Import/Export
The official files from the IGS have the extension ERP. Because the internal Bernese pole
files have the same default extension but a different format the IERS pole files have to
be renamed to a filename with default extension IEP before conversion to Bernese format
(for a description see Section 22.7.8). The conversion is performed using program POLUPD
(”Menu>Orbits/EOP>Handle EOP files>Convert IERS to Bernese format”) which supports not only the IGS
version 2 format, the formats of the IERS C04, and of the IERS Bulletin A and B, but
about 20 foreign formats. For details see Section 5.2.2.
Pole files in IGS format version 2 are written by programs GPSEST and ADDNEQ2 (in
addition to pole files in Bernese format). Program POLXTR (”Menu>Orbits/EOP>Handle EOP files
>Concatenate IERS pole files”) extracts pole information from a series of consecutive IERS pole
files and writes a combined pole file in IGS format.
4.6 SINEX
4.6.1 Definition
At the 1994 IGS Workshop on the Densification of the IERS Terrestrial Reference Frame
through Regional GPS Networks (JPL, Pasadena, December 1994, [Blewitt et al., 1994]), it
Page 68 AIUB