NATIONAL REPORT OF THE FEDERAL REPUBLIC OF ... - IAG Office

102 Commission 4 – Positioning and Applications
dramatically improved the coherence of GNSS to the other
geodetic space techniques results.
During the past four years the German research institutes
mainly consolidated their contributions to the network of
continuously recoding permanent stations. The Geo-
ForschungsZentrum Potsdam (GFZ) extended its High-
Rate/Low-Latency (HR/LL) GPS ground tracking network
established jointly by GFZ and JPL to ensure adequate
ground data availability for CHAMP and GRACE satellite
missions to 15 stations. New real time stations are planned
and partly installed within the South East Asia-Indian
Ocean region as part of the Tsunami Warning System
GITEWS. The large scale network SAGA for geodynamics
in the Southern and Central Andes was extended and
densified with new continuous sites and epoch stations with
an anticipated resolution of 50 km in seismic gap regions.
The Federal Agency of Cartography and Geodesy (BKG)
upgraded part of its IGS and EUREF sites and installed a
continuous local monitoring network for the TIGO fundamental
station in Conception, Chile.
Several Universities participated in international research
and programmes which included the installation of new
permanent GPS stations. TU Dresden was active in the
Arctic Peninsula region. TU Karlsruhe focussed on Brazil,
the Vranca deformation zone in Romania and the Upper
Rhine-graben in Germany. TU Darmstadt installed one
permanent site in cooperation with the University of
Bucharest in Oradea, Romania in Romania as part of the
Central European Geodynamic Reference Network
CEGRN.
A major novel approach was the rapid development of the
NTRIP-based streaming real time GNSS data system by
BKG. At the beginning of 2007 raw data or corrections of
about NTIRP 1850 stations were available at 80 casters
worldwide. Due to the standardization of the NTRIP transfer
protocol in September 2004 a huge user community in
science and industry utilizes these data stream. New appli-
cations for real time clock and orbit products are under
development. The BKG German base network GREF with
its 19 stations is completely transferred to the real time
streaming data delivery by use of NTRIP and corresponding
DGPS correction data are streamed via NTRIP casters as
well.
GNSS based techniques are used for atmospheric sounding
since several years but within the reporting period a breakthrough
for the use of GPS based atmospheric data for
various applications in atmospheric research occurred.
Since 2006 the GPS occultation data from COSMIC,
GRACE-A and CHAMP are operationally used of by the
European Centre for Medium-Range Weather Forecasts
(ECMWF) to improve global weather forecasts. GFZ Potsdam
contributed significantly by the CHAMP satellite
mission, data analysis techniques, applications and also
assimilation techniques were developed and improved.
Presently GRACE and the data of the COMSIC constellation
are under investigation and in preparation for the
operational use.
Space based applications are supported by the continuous
provision of near-real time atmospheric data from a regional
German network, processed at GFZ for inclusion to the
European E-GVAP action, to push the use of GPS ground
data for numerical weather prediction (EUMETNET-GPS
water vapor program, within the network of the European
Meteorological Services). Since 2006 these data are assimilated
at MeteoFrance and additional weather services will
join in 2007.
Research is dedicated also to the novel application of
reflected GNSS signals in the altimetry/scatterometry
approach, where lake levels were monitored with an
accuracy of ~2 cm. Further promising perspectives are
ground and space based applications in geoscience and
atmospheric research, e.g. on ice surface properties (roughness),
ice coverage of oceans, sea surface heights, significant
wave height and wind speed/direction above sea
surfaces are feasible and under investigation.