Fundamental Station Wettzell - geodetic observatory -

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1 Fundamental Station Wettzell - geodetic observatory - Wolfgang Schlüter Bundesamt für Kartographie und Geodäsie, Fundamental Station Wettzell Germany Radiometer Workshop, Wettzell,

2 Evolvement of Geodetic Space Techniques Progress in accuracy through space techniques 1960 Satellite Triangulation (first global network) ~10 m 1970 Satellite Laser Ranging 1. Gen. ~1 m TRANSIT (Doppler) ~ m 1980 Satellite Laser Ranging 3. Gen. ~3 cm Very Long Baseline Interferometry (VLBI) ~3 cm 1990 SLR/VLBI/GPS progress ~1 cm 2000 Combination of Space Techniques ~3 mm Progress is based on technology developments of the last decades Laser technology Electronic signal processing IT developments (VLBI: data recording, ) T&F (atomic clocks, frequency generator, time transfer) Etc... High Accuracy opens new fields for research and applications

3 Changing Earth - Interactions Mantle Convections Plate Motion Volcanism Sea level Rise Ice melting Warming up Tides (Moon, Sun, Planets) Ocean tides Earth tides Ocean Mass transport Loading Atmosphere/Wind Mass transport Loading Groundwater changes Variations in Positions, Gravity Field, Earth Rotation

4 Continuous observations required Monitoring the variations Improve the models (predictions) Understanding of geophysical phenomena Maintenance of global reference frames for positioning in Space and on Earth Quasar, Stars, Planets, Moon...) Space Crafts, Satellites,... ) Geodesy Geo-Information Navigation.. Fundamental for Research in all Geosciences and related disciplines IAG-PP: GGOS (Global Geodetic Observing System) global reference frame, 10-9 precise consistent in geometrical and physical parameters! consistent for decades!

5 Global Reference Frames ICRF: International Celestial Reference Frame Quasar Positions ITRF: International Terrestrial Reference Frame Position Coordinates Velocity Vector EOP: Earth Orientation Parameter Precession/Nutation Polar Motion UT1 - UTC Earth Rotation combines ICRF and ITRF GGOS extension to Gravity Field etc.

6 Geodetic Space Techniques VLBI VLBI (Very Long Baseline Interferometry) SLR/LLR Satellite/Lunar Laser Ranging GNSS (GPS, GLONASS, future: Galileo) DORIS (Doppler Orbitography and Radio Positioning Integrated by Satellite) SLR/LLR GNSS/GPS DORIS

7 International Cooperation: IAG-, IAU- Services The maintenance of global reference frames is a very complex and a global task, which can only be solved on the international level. In the last years, international services were established by the individual techniques, in the frame of the International Association of Geodesy (IAG) or International Astronomical Union (IAU), in order to coordinate the observations, the data flow, the analysis and the development of technology. The services are the Geometric Services International GNSS Service (IGS), International Laser Ranging Service (ILRS), International VLBI Service for Geodesy and Astrometry (IVS) International DORIS Service (IDS) and the Combination of the products by International Earth Rotation and Reference Frame Service (IERS). IAG-PP: GGOS (Global Geodetic Observing System) needs also Gravimetric Services International Gravimetric Bureau (BGI) International Center for Earth Tides (ICET) Permanent Service for Mean Sea Level (PSMSL) International Gravity Field Service (IGFS)

8 RMS of Geodetic Space Techniques (From a global TRF solution derived by DGFI, Munich)

9 VLBI for Geodesy and Astrometry Observable τ Simultaneous observations of Quasars Recording of radio signals transmitted from quasars (satellites) S/X-band VLBI2010: broadband 2-18GHz IVS observing Program R1... R4.. R&D, CONTxx, INT etc. Data transfer to Correlator Courier e-vlbi Correlation process provides τ Products: Baselines Station coordinates and velocities Earth Orientation Parameter (EOP) Quasar positions, variations tropospheric parameter physical parameters etc.

10 Map of the IVS Components

11 SLR/LLR Observable: propagation time t of a Laser pulse between the transmission from the SLR/LLR system, reflection at the target (satellite, Lunar) and receiving of the returns at SLR/LLR system Nd: Yag- or TiSapp- Laser(2 Wave lengths) 10Hz-, future 1kHz- repetition rate Products station positions with respect to the center of mass, velocities polar motion precise satellite orbits gravity field physical parameter etc.

12 ILRS- Global Network

13 GNSS: GPS, GLONASS, Navigation -Pseudo ranges DGPS - simultaneous observations Geodesy - phase observations Products station positions, velocities satellite orbit polar motion, LOD atmosph. parameter ionos. parameter. etc.

14 IGS-global Network

15 Fundamental Stations Wettzell und TIGO Collocation of geodetic space techniques control complementary continuous unification of ITRF local ties FS-Wettzell VLBI, SLR, GPS: Matera, Italy Shanghai, China Keystone, Japan Hartebeesthoeck,S.- Afrika Greenbelt, USA TIGO

16 Tasks of F S W Provision of Observations Contribution to International Programs Space Techniques Very Long Baseline Interferometry (VLBI) Laser Ranging to Satellites and Moon (SLR/LLR) Microwave techniques (GPS, GLONASS, DORIS, PRARE) In situ observations (T&F, Gravimetry, Meteorology, Seismography) Operation of TIGO in Chile Operation of GARS O Higgins Operation of permanent GPS/GLONASS Stations Development of the techniques (e.g. SOS_W) Development of new observing methods (Ringlaser)

17 Research Group Satellite Geodesy (FGS) Agreement on Cooperation Bundesamt für Kartographie und Geodäsie (BKG) Deutsches Geodätisches Forschungsinstitut (DGFI) Technische Universität München (TUM) Institut für Astronomische und Physikalische Geodäsie (IAPG) Forschungseinrichtung Satellitengeodäsie (FESG) Geodätisches Institut der Universität Bonn (GIUB) Operation of Fundamentalstation Wettzell by Bundesamt für Kartographie und Geodäsie (BKG) Forschungseinrichtung Satellitengeodäsie (FESG)

18 VLBI-Activities 9m O Higgins 20m RTW 6m TIGO Observations FSW > 3,5 d/w a 24h INTENSIVES TIGO > 2.5 d/w a 24h O Higgins (campaigns) Maintenance Highly reliable operations Equipped with MK5 data acquisition systems e-vlbi (Internet, INT) Future Developments TWIN telescope IVS- Next Generation VLBI (VISION 2010)

19 WLRS: Wettzell Laser Ranging System 75cm Telescope LAGEOS Reflector on the Moon Satellites LAGEOS1 LAGEOS2 Starlette Stella ETALON1 ETALON2 GPS35 GPS 36 6 GLONASS ERS1 ERS 2 ENVISAT AJISAI BEACON TOPEX Moon ILRS NASA Apollo missions Russian missions

20 SLR/LLR activities WLRS TIGO-SLR SOS-W Continuous observations WLRS: 24h per day, all over the year 360d TIGO: ~24h per day, all over the year Maintennance For robust operation Quality Control Development of the new SLR- Systems SOS-W state of the art automatic operation Ti Sapp-Laser 1kHz-repetition rate

21 GPS/GLONASS - FSW GREF IGS EUREF

22 GPS time series

23 Time and Frequency (T&F) Cs-standard T&F-control board Epoch 10ns with reference to UTC Frequency absolute relative Time systems 5 Cs-standards 3 H-Maser GPS-time transfer H-Maser UTC(Wettzell)

24 TIGO, Transportable Integrated Geodetic Observatory Since April 2002 VLBI: operation for IVS SLR: operation for ILRS GPS: operation for IGS

25 GARS O Higgins German Antarctic Receiving Station BKG und DLR VLBI GPS/GLONASS tide gauges

26 Ring Laser /Laser gyroscope local sensor for rotations daily variations of Earth rotation real time data access co-operation: BKG, FESG, Univ. Canterbury

27 G

28 Underground Laboratory G

29 View from the outside

30 Results G

31 Thank you