Acta Geodaetica et Cartographica Sinica ›› 2017, Vol. 46 ›› Issue (4): 430-435.doi: 10.11947/j.AGCS.2017.20160506

Previous Articles     Next Articles

Crustal Subsidence Analysis from GNSS Data for Dagang Tidal Station in Qingdao

WU Fumei1,2, WEI Ziqing1,2, LIU Guangming1,2   

  1. 1. State Key Laboratory of Geo-information Engineering, Xi'an 710054, China;
    2. Xi'an Research Institute of Surveying and Mapping, Xi'an 710054, China
  • Received:2016-10-13 Revised:2016-12-15 Online:2017-04-20 Published:2017-05-05

Abstract: Crustal subsidence at Dagang tidal station affects the Huanghai mean sea level which defines the national height datum. The crustal subsidence at Dagang tidal station located 1.5 km away from Qingdao GNSS fiducial station is analyzed, by using approximately 10 years of GNSS observations. Firstly, the daily relax solutions and daily constrained solutions for coordinates of this station are computed in a combined adjustment involving a global GNSS net of 50 IGS stations and a regional net of 43 CMONOC stations. Then, a time series spanning 10 years for station coordinates aligned to ITRF2014 is obtained. And next, the time series of height components is analyzed to detect outliers, offsets, trends and frequencies and the amplitudes of periodic parts and the values of offsets are obtained. It is shown that no trend is found in the series. But it is found that the annual and semi-annual signals influence the changes of the series obviously. Finally, it is concluded in combination with the analysis of tidal data for Dagang tidal station that the mean sea level at Dagang tidal station is ascending with a speed of 1.62 mm/a.

Key words: height datum, GNSS station, time series, crust subside

CLC Number: