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Regional Models

Turkey (Turkey-ITUGRG2021)

  Authors: M.S. Işık et al.     Created: 2021    Resp: B. Erol  
      Status: PRIVATE    
The Turkey-ITUGRG2021 model is a gravimetric geoid of Turkey, computed by the Gravity Research Group in Department of Geomatics Engineering, Istanbul Technical University (ITU-GRG). The area covered by the models is 26°E ≤ longitude ≤ 45°E, 36°N ≤ latitude ≤ 42°N with a grid spacing of 3' in both latitude and in longitude. The computation is based on the Least Squares Modification of Stokes Integral with Additive Corrections (LSMSA). In the computation, the XGM2019 global geopotential model up to degree/order 360 is used. The integration radius for Stokes integral is chosen as 0.25°. The error degree variance of gravity anomalies is constructed using a band-limited white noise model where standard deviation is taken as 5 mGal. The topographic effect on the gravity data set is handled using SRTM2Grav global model of gravimetric terrain correction (Hirt et al., 2019). The accuracy of the geoid model over 100 GPS/leveling that covers the entire country is 10.1 cm (before-fit) and 8.6 cm (after 7-parameter fit).

M.S. Işık, S. Erol, B. Erol (under review). Investigation of the geoid model accuracy improvement in Turkey. Submitted to Journal of Surveying Engineering.
C. Hirt, M. Yang, M. Kuhn, B. Bucha, A. Kurzmann, R. Pail (2019). SRTM2gravity: An ultrahigh resolution global model of gravimetric terrain corrections. Geophysical Research Letters, 46(9), pp. 4618-4627. DOI: 10.1029/2019GL082521