Verification of the meteorological observations on the EPN stations

Transcription

1 Institute of Geodesy and Geoinformatics Wroclaw University of Environmental and Life Sciences Verification of the meteorological observations on the EPN stations Jarosław aw Bosy Witold Rohm EUREF 2007 SYMPOSIUM LONDON 1/24

2 Contents Meteorological data reliability assessment, Validation of stations log files, EPN stations RINEX meteo data files and NOAA climate Global Summary Of the Day (GSOD) stations data files, Verification of common stations list: synoptic and GPS stations, Comparison of ZTD obtained from mean EPN solutions and local meteo data EUREF 2007 SYMPOSIUM LONDON 2/24

3 Meteorological parameters: stations positions EPN stations with meteorological sensors synoptic stations EUREF 2007 SYMPOSIUM LONDON 3/24

4 Meteorological parameters: sources, year 2006 meteo sensors mounted close to GPS antena pressure: hpa temperature: C humidity: 3-5% National Meteorological Services (working in the WMO network) pressure: 0.2 hpa temperature: C humidity: 2% GPT model pressure: 5 hpa temperature: 3 0 C EUREF 2007 SYMPOSIUM LONDON 4/24

5 Meteorological parameters in different climatic zones meteorological parameters /climatic zone T temperature [ 0 C, 0 K] P pressure [hpa, mbar] frigid maritime (oceanic) REYK not avalible warm maritime (subtropic) MATE EUREF 2007 SYMPOSIUM LONDON 5/24

6 Meteorological parameters in different climatic zones with continental influences frigid SVTL with continental influences warm TRAB mountain SNEC EUREF 2007 SYMPOSIUM LONDON 6/24

7 Meteorological parameters: data interpolation comparison and calibration compensate for recalculation to mean sea level on some synop stations GPS antenna position compensate for synop station vertical distance GPS antenna position position of synoptic station mean sea level 16 m 124 m 13 m position of pressure sensor EUREF 2007 SYMPOSIUM LONDON 7/24

8 Meteorological parameters: data interpolation,comparison and calibration Meteo labs on GPS stations NMS synoptic stations Model Examples of data resolution interpolate to similar resolution (1 h) compensate for sensor displacement 24h average compensate for recalculation to mean sea level on some synop stations compensate for synop station vertical distance calculate GPT model values (p,t) Station WROC GOPE BISK SNEC meteo files time resolution [s] correcting 1 hour observations with mean day difference calculating corrections plotting EUREF 2007 SYMPOSIUM LONDON 8/24

9 station Meteorological parameters: results of calibration Bias is a mean difference between calibrated and not calibrated data Error is a standard deviation of difference between calibrated and not calibrated data bias press (hpa) error press (hpa) bias temp ( 0 C) error temp ( 0 C) lama karl helg wtzr orid mate pdel pots mets ptbb reyk NaN NaN bisk sass casc snec delf sofi eusk svtl gaia trab wroc tubo hers warn hert gope ista nico joz2 kraw data with bias above 1 hpa or 1 0 C EUREF 2007 SYMPOSIUM LONDON 9/24

10 Problems: Station list Using the list of coupled meteorological and GPS stations Surface meteo observations from the European Centre for Medium Range Weather Forecasts (ECMWF) for the STARTWAVE atmospheric water database Stefan Wacker very useful sometimes with mistakes (HERT, PTBB, REYK): The height of GPS point ellipsoidal not msl (as stated) EUREF 2007 SYMPOSIUM LONDON 10/24

11 Problems: EPN stations log files Height Different to Ant : measurement not unified (examples): KARL, HERS, DELF, TUBO, GOPE KARL TUBO Data Sampling Interval: information about values HERS EUREF 2007 SYMPOSIUM LONDON 11/24

12 Problems: EPN stations log files unnecessary units after values problems with data reading: log file construction description GAIA showing sensor but not transferring data to EUREF data center: log file UNPG BGK data center site? EUREF 2007 SYMPOSIUM LONDON 12/24

13 Problems: EUREF stations meteorological data huge data gaps on some stations: NSSP EUREF 2007 SYMPOSIUM LONDON 13/24

14 sensor damage (BISK) Problems: EPNE stations meteorological data BISK sensor probably under temperature strong influence (LAMA) LAMA EUREF 2007 SYMPOSIUM LONDON 14/24

15 Problems: Synoptic stations data missing data on NOAA server or OGIMET (examples): Legionowo Ankara, Yerewan recalculation to mean sea level not always successful POTS, WROC POTS WROC EUREF 2007 SYMPOSIUM LONDON 15/24

16 Problems: other PDEL - temperature NICO - pressure EUREF 2007 SYMPOSIUM LONDON 16/24

17 Tropospheric Delay: Sources EUREF ZTD: weekly mean solution from all EPN LAC s ZTD based on the local meteo: Saastamoinen model: ZWD 1255 = e0[ hpa] T0[ o K] ZTD = ZWD + m Po hpa ZHD = cos 2ϕ h km ZHD EUREF 2007 SYMPOSIUM LONDON 17/24 e

18 Tropospheric Delay: Comparison WROC: year 2006 EUREF 2007 SYMPOSIUM LONDON 18/24

19 Tropospheric Delay: Comparison GOPE : year 2006 EUREF 2007 SYMPOSIUM LONDON 19/24

20 Tropospheric Delay: Comparison SNEC : year 2006 EUREF 2007 SYMPOSIUM LONDON 20/24

21 Tropospheric Delay: Comparison BISK : year 2006 EUREF 2007 SYMPOSIUM LONDON 21/24

22 Conclusion 31 EPN stations (from all number of 184) transferring meteorological data to Data Centres. Some station have problems with sensors (BISK, LAMA); Most of the station logs are not easily for automatic reading and the log s files need unification; Problems with height measurements on synoptic stations (pressure bias POTS, NICO, WROC); Pressure data accuracy varies from almost zero bias and 0.2 hpa error to bias 24 hpa on BISK station and error 11 hpa on LAMA station; Temperature data accuracy varies from almost zero bias and C error to bias C on PDEL station and error C on LAMA station; Some biases have unclear source (NICO, PDEL) and need to be investigated in the future. EUREF 2007 SYMPOSIUM LONDON 22/24

23 Institute of Geodesy and Geoinformatics Wroclaw University of Environmental and Life Sciences Thanks for your attention EUREF 2007 SYMPOSIUM LONDON 23/24