[IGSMAIL-5899]: swrx data announcement

[Thomas Pany]

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IGS Electronic Mail      13 Feb 08:54:00 PST 2009      Message Number 5899
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Author: Thomas Pany, Carsten Stoeber, Klaus Boerger

Following the discussion of the last IGS workshop in Miami, we'd like to
announce that GPS/Galileo RINEX observation files produced by a PC-based
software receiver are available at CDDIS in a test mode.

In contrast to the current GNSS receivers used by the IGS, a PC-based
software receiver does all signal processing on the PC and requires only
a minimum amount of front-end hardware. Thereby it cuts hardware costs
drastically and allows an easier implementation of new signal processing
algorithms. In future, a software receiver could also be realized as an
open source project giving the IGS community full insight, thereby allowing
to refine existing pseudorange error models.

To foster research in this area, Carey Noll was so kind to provide a
directory to put 1s RINEX files from two software receivers located in
Germany and running on a Dell T7400 computer. They track GPS C/A on L1,
GPS Civil Signal (CM) on L2 (from the II-RM satellites only), GIOVE-A Open
Service (B+C) on E1, GIOVE-A Open Service (I+Q) on E5a and one EGNOS
satellite. The software was developed at the University FAF Munich and was
funded by the German Federal Armed Forces (AGeoBw and WTD81) and partly by
DLR. It is not open source. Data is provided since DOY23 2009. Data for
DOY1 is made available too, which contains E5a data (so far, GIOVE-A did
not broadcast E5a after DOY23).

We would be highly interested to receive feedback of any kind on the quality
of the data, which will be of importance for the further developments.
Although a software and hardware receiver operate on the same kind of
digital signals, the implementation constraints are different. This affects
multipath mitigation, correlation and the real-time behavior under Windows.
Thus, it would be helpful and important to assess the impact on high-
precision products.

The data is located at
ftp://cddis.gsfc.nasa.gov/gps/data/swrxtest
where station log files can be found and a summary of the signal processing
and multipath mitigation settings. RINEX files are provided using both
3.0 and 2.11 formats in parallel directory trees. The provision of the data
from station IF5B will not be continuous, but data from the station EUSS
(co-located to the EUREF site EUSK) can be provided further by the courtesy
of the AGeoBw. In the near future a software update for GIOVE-B and the GPS
L5 test signal is planned.


Thomas Pany, Carsten Stoeber (University of Federal Armed Forces Munich,
Germany)

Klaus Boerger (AGeoBw, Federal Armed Forces, Euskirchen, Germany)