|ثبت ژئوئید محلی ایران تحت عنوان IRG2016 در سرویس بین المللی ژئوئید ISG وابسته به GFZ
Services - Geoid
Authors: S. Abdoreza Saadat, et al.
Resp: S. Abdoreza Saadat
IRG2016 is a geoid model for Iran,
computed by the National Cartographic Center (NCC) and bounded between
25°E and 40°E in
latitude and between 44°N and 63.5°N in longitude. It is
modelled by radial basis functions (RBFs), requiring the determination
of their type and number, their horizontal positions, depths,
and unknown coefficients. The input observations were 21525
data supplied by the NCC of Iran. Residual surface gravity
disturbances were computed by subtracting the EIGEN-6C4 model up to
degree and order
360 and were used to determine the unknown RBF parameters by
the stabilized orthogonal matching pursuit (SOMP) algorithm. The RBF
used to calculate the residual height anomalies. Thus, the
residual geoidal height was determined by applying the residual
Finally the effect of the long-wavelength part from EIGEN-6C4
was restored. The IRG2016 model was fitted to 1288 GNSS/levelling
control points over Iran by
applying the polynomial corrector surface. The resulting height
reference surface shows an RMS value of approximately 23 cm for the
difference in geoidal
height at the independent control points.
The 2.5' x 2.5' gridded IRG2016 model (gravimetric and hybrid
versions) is on-demand available at the ISG website, while the model
interpolation (point-wise or
providing an input file) can be performed by an online calculator, according to the NCC policy rules.
S.A. Saadat (2016). Regional gravity field modeling combining
terrestrial and satellite gradiometry data based on radial basis
functions. PhD thesis in Geodesy at University of Tehran, Iran.
A. Saadat, A. Safari, D. Needell (2018).
IRG2016: RBF-based regional geoid model of Iran. Studia Geophysica et
Geodaetic, 62, DOI: 10.1007/s11200-016-0679-x