Bernese GPS Software Version 5.0 - Bernese GNSS Software

5.3 Preparation of GNSS Broadcast Information
based on measurements provided by the space geodetic techniques. You do not need this
file at all if you use IGS pole information or the C04- or the Rapid-pole (Bulletin A) from
http://www.aiub.unibe.ch/download/BSWUSER50/GEN/.
Figure 5.2 displays the settings of the relevant options for running the program POLUPD.
The options “Nutation model” and “Subdaily pole model” specify the type of model you use to
apply the nutation correction parameters and subdaily pole variations. Nutation corrections
may be given in columns DEPS and DPSI of the ERP file (to be created here). These corrections
may stem from VLBI observations (e.g., in IERS Bulletin A) or from GPS observations
computed by means of the Bernese software (research purpose). It is recommended not to
use these offsets and to disable option “INCLUDE NUTATION OFFSETS”. This choice prevents
the use of nutation correction information. Subsequent computations are then solely based
on the nutation model specified in “Nutation model”.
In case you use the values of IERS Bulletin B, the option “Use 1 or 5 day values” allows you
to select the daily Earth rotation parameters or the values given in a five day interval.
Option “USE ERP RATES” may be activated in order to use the ERP rates given in the IGS
format to generate additional pole records at the beginning and end of a day. This option
should, e.g., be used if you convert IGS Rapid Pole files (IGR), because these files only
contain one record at 12:00 UT. By enabling this option you obtain a Bernese pole file with
three records (at 0:00, 12:00, and 24:00 of the day).
Program POLXTR (”Menu>Orbits/EOP>Handle EOP files>Concatenate IERS pole files”) extracts ERP information
from a list of consecutive pole files in the IGS format and allows to specify an
a priori pole file which may be used for comparison purposes. We refer to the corresponding
help panel for details.
5.3 Preparation of GNSS Broadcast Information
Due to the fact that precise orbit information is available for GPS and GLONASS from the
IGS (or from CODE), broadcast information needs not to be considered for normal GPS
data processing (and since the availability of high-quality Ultra-Rapid IGS Orbits not even
for near real-time applications). Nevertheless the Bernese GPS Software contains programs
to concatenate, convert, and analyze broadcast navigation messages.
Broadcast messages from individual receivers only contain messages for the observed satellites.
In order to obtain a full set of RINEX messages the messages from globally distributed
receivers need to be concatenated. This can be accomplished using the programs
CCRINEXN (”Menu>RINEX>Cut/concatenate RINEX files>Navigation files (GPS)”) for GPS and CCRINEXG
(”Menu>RINEX>Cut/concatenate RINEX files>Navigation files (GLONASS)”) for GLONASS.
5.3.1 Standard Procedure
The standard procedure in Version 5.0 for introducing broadcast orbit information for GPS
and GLONASS into the Bernese GPS Software is the conversion of the navigation messages
into the precise file format (SP3). For this purpose a program called RXNPRE (”Menu>RINEX
>Import RINEX to Bernese format>Navigation files to SP3”) is used. The program can either convert
Bernese GPS Software Version 5.0 Page 87