Evaluation of height network in Latvia

Transcription

1 Evaluation of height network in Latvia Kaminskis J. (,), Balodis J. (), Janpaule I. (,), Normand M. (,), Rubans A. (), Silabriedis G. (,), Zvirgzds J. (,) AFFILIATION: () Riga Technical University; () Institute of Geodesy and Geoinformation, University of Latvia; () Latvian Geospatial Information Agency; () Rigas GeoMetrs Ltd.

2 OUTLINE.Levelling campaigns in Riga city.height determination of levelling benchmarks.the control measuring campaign using EUPOS Riga and LATPOS RTK network.. The daily result distribution during two month period (Jan-Feb, ).. The LATPOS base station OJARS. Hourly result distribution during day period September.. Preliminary results.. The st order levelling benchmark monumentation in Latvia.. The control measuring campaign using EUPOS Riga and LATPOS RTK network.. Results.Conclusion for RTK.The analysis of precise levelling and Earth s crust vertical movement.selection of zero point (reference point with zero vertical motion).the reference points of geodetic heights. Interoperability of height systems 9.Additionally re-measured EUVN points

3 . Levelling campaigns in Riga city Last nd order levelling campaign in Riga city was performed at 9-. Mainly negative vertical movement was discovered at several places comparing with levelling results of 99-. There were no levelling networks neither controlled nor developed in Riga city after 9. However, the high accuracy levelling network is still important for many civil engineering tasks and for geodetic and geophysical research purposes. The deformation of Riga levelling network may be caused by: -the vertical movement of local earth surface; -the tectonic continental and intercontinental movement of the earth core is available as well. -there are several effects of vertical movement in urban environment. -development of the new building construction; -increase of traffic intensities and -both the geologic and hydro geologic conditions in upper layers of ground are additional sources of the up or down movement of earth surface.

4 . Height determination of levelling benchmarks The vertical movement could be controlled by height determination of levelling benchmarks. Application of Global Navigation Satellite Systems (GNSS) in geodesy discovers a powerful tool for the verification and validation of the historically long time ago established geodetic levelling benchmarks. The differential GNSS and RTK methods appear very useful to identify the vertical displacement of landscape by means of inspection of the deformation of levelling networks. The criteria of Mean Sea Level not always is highly useful. The mean Baltic Sea level has risen by cm during years according the records of Riga tide gauge station. It is placed near the Daugava river estuary where the water level changes depending of the work regime at the Riga hydroelectric power station placed on the Daugava river at a distance of about km. Therefore it is rather difficult to fix the real value of mean sea level near Riga. It is influenced by the artificially changing water level of river Daugava.

5 . Height determination of levelling benchmarks Additional tool for the independent height determination is the application of Satellite Laser Ranging System (SLR) recently developed at the University of Latvia. The SLR is located at the centre of EUPOS Riga base station network at a distance of m from GNSS antenna (in the centre of our capital).

6 . Height determination of levelling benchmarks The relevant volume of SLR ranging data will be collected and the proper height determination tests will be performed. The laser ranging accuracy of LAGEOS and other LEO satellites appears at the subcentimeter level. Date Satellite RMS cm RMS cm NP RMS cm 9.. Ajisai Jason Ajisai Ajisai Jason 9... Lageos.9. LAGEOS (d= cm)..9 Lageos....9 ERS Lageos 9.. LAGEOS visible in SLR telescope guide at a distance of km.. ENVISAT.... ERS Jason..

7 . The control measuring campaign using EUPOS Riga and LATPOS RTK networks EUPOS -Riga - base stations - distance between stations ~ km Riga's GeoMetrs Ltd. and Institute Of Geodesy and Geoinformation /University of Latvia/ LATPOS - 9 base stations - distance between stations ~ km Latvian Geospatial Information Agency

8 S S S S S 9 S S S S S S S S S NKG General Assembly.. The daily result distribution during two month period (Jan-Feb, ) EUPOS-Riga antennas calibrated Lu ( Northing ) RMS=, mm Lu ( Easting ) RMS=, mm Lu ( Up ) RMS=, mm Centre (LU) N, E, U: STDV mm ={.,.,.} Kre ( Northing ) RMS=,9 mm Kre ( Easting ) RMS=, MM Kre ( Up ) RMS=, mm North (Kre) N, E, U: STDV mm ={.9,.,.} Msk (Northing) RMS=,9 mm Msk (Easting) RMS=, mm Msk ( Up ) RMS=, mm South (Msk) N, E, U: STDV mm ={.9,.,.} Van ( Northing ) RMS=, mm Van ( Easting ) RMS=, mm Van ( Up ) RMS=, mm East (Van) N, E, U: STDV mm ={.,.,.} Series Series - - S Ann (Northing) RMS=, mm Ann (Easting) RMS=, mm Ann (Up) RMS=, mm West (Ann) N, E, U: STDV mm ={.,.,.}

9 NKG General Assembly.. The LATPOS base station OJARS. Hourly result distribution during day period September Antenna not calibrated OJARS (Northing) OJARS (Easting) 9 9 S S Series Series Series Series OJARS (Up) OJARS N, E, U: STDV mm = {.,.,.} S Series Series

10 Kre Van Lu Ann 9 T Msk 9 9 Kre Ann Differences ( cm ) Lu Van T Msk South <- North NKG General Assembly.. Preliminary results Arrangement N -> S West -> East, -, -, -, Epoch precision and reliability Rp 9 one measurement RMS=, cm ( measurements) result RMS=, mm -, -, -,

11 .. Preliminary results Preliminary results have discovered a land down lift at the bank of Riga Bay THEREFORE Further measurements and research was performed during summer.

12 .. The st order levelling benchmark monumentation in Latvia Fundamental ground benchmark Ground benchmark

13 .. The control measuring campaign using EUPOS Riga and LATPOS RTK networks

14 .. Results points (st order and nd order levelling benchmarks) were measured using LEICA and TOPCON GPS receivers The sequence of results of RTK sec long sessions were collected and/or The sequence of results of RTK sec long sessions were collected

15 Collecting results of RTK sec long sessions in Riga at the Rainis monument

16 Variation in m NKG General Assembly.. Results STDV= RMS= n Results STDV RMS STDV RMS # H mm mm mm mm, 9,,,, 9,9,,,, 9,9,,,, 9,,,,9,, 9,,,,, 9,9,,,9, 9,9,,,,9,,,,, 9, 9,,,,,,,,,,, 9,,, SALA,,, T,9,,9,,,,,,,,99,99,9,9,9,9,9,9,9,,,,,, Sequence of results of RTK sec long sessions, probably influenced by ionosphere fluctuations 9 9 Sequence of results of RTK sec long sessions () Sequence of results of RTK sec long sessions (),9,9,9,9,9,9,

17 .. Results Levelling Year dh (m) Levelling Year dh (m) # st order st order nd order nd order,9 9, 9, 9, 9, -, 9, -, 9, -,,9 9, 9, -, 9, -,, 9 -, 9, 9,, -, 9, -,, -, The coherence of results (st and nd order of benchmarks; year 9,,,, ) is within cm Mainly the values with negative sign have been observed, -,,,,, 9, 9 -, SALA,9, T, 9 -,,,

18 Deformation ( m ) NKG General Assembly.. Results Control Results,,,, -, -, SALA T -, -, st order nd order

19 . Conclusion for RTK,,,,,,,, LEVELLING using traditional methods / using RTK application ~ km; ~ km; days work of levelling team week work,,, 9,,,,,

20 . The analysis of precise levelling and Earth s crust vertical movement Acquired and allowed (in blue color) discrepancies of polygons

21 . The analysis of precise levelling and Earth s crust vertical movement Earth s crust vertical movements in a year period in [mm] (represented with isolines)

22 Scientific and historical motivation. Selection of zero point (reference point with zero vertical motion) Earth s crust movement in Baltic states (O. Jakubovskis, G. Žeļņins, I.Liešs un V. Matskovs). The results from levelling materials (9 99) tied with sea level observation data (research of O. Jakubovskis). The data of precise levelling in the territory of Latvia and Lithuania ( - 9) (research of G. Zelnins and I. Liess). The isolines of Earth s vertical movement for a year period (research of V. Matskovs)

23 . Selection of zero point (reference point with zero vertical motion) Zero line of Earth s crust vertical movement

24 . Selection of zero (reference point with zero vertical motion) point The fundamental benchmark is determined as the most suitable height zero point, Fr, in Sloka, its height is. m (BHS) and. m (EVRF) Difference, cm between systems

25 . The reference points of geodetic heights

26 . Interoperability of height systems The predicted height differences between BHS and EVRF

27 9. Additional measured points EUVN_DA ETRFyy ETRFyy ETRFyy LV9 EGG NKG normal height of Remarks N.p.k. Station name identifier lat lon ellipsoidal height [m] Geoid Geoid Geoid EUVN_DA station char. [deg] [deg] tide free zero tidal model model model EVRF EVRF Skulte LV,9,,, 9, 9,9 9,,, Liepaja LV,9,9,,9,,,9,, Ventspils LV,99,9,9,,,,,9, Irbene LV,,99,,9,,, 9, 9, M RIGA,99,,,,9,,,, gp LV,,99,,,,,,, gp LV,,99,,,9,,99,, gp LV,,,,9,,9,9,, 9 gr LV,99,9,,,,,,, - Aloja LV,,9,,9 9,9 9, 9,9,, Behova LV,9,,,,9,, 9, 9, Indra LV,9,,,,,, 9, 9,9 Jaunjelgava LV,9,,,9,9,, 9, 9, - Kangari LV9,99,9,, 9, 9, 9,,,9 Kolka LV,9,,9,,,9,9,99, Nesaules LV,9,9,,,,,,,9 Pastari LV,,99,,,9,9, 9,9 9,99 Pavari LV,9,9,,,,9,,, 9 Riga LV,9,9 9, 9,,9,,,, Slamste LV,,,,9,,,9,9, Mean values 9,9 9,9,,,,9, +, cm +, cm

28 9. Additional measured points Dispersion of height measurements during session KOLKA (m),,,,,,,, Ellipsoidal height =, m +, cm

29 9. Additional measured points Dispersion of height measurements during session gr (m),,,,,,,,, Ellipsoidal height =, m -, cm

30 9. Additional measured points Dispersion of height measurements during session JAUNJELGAVA (m),,,9,,,,,,,,, Ellipsoidal height =, m +, cm

31 9. Additionally measured EUVN points

32 THANK YOU FOR KIND ATTENTION!