The ITU quasi-geoid based on Least Squares modification of Stokes integral with additive corrections for the Colorado Experiment: ColLSMSA2020

The ColLSMSA2020 gravimetric quasi-geoid model has been computed by the Gravity Research Group of the Department of Geomatics Engineering, Istanbul Technical University (ITU-GRG). The model has been computed in the frame of the International Association of Geodesy Joint Working Group 2.2.2 "The 1 cm geoid experiment". The area covered by the model is 109°W ≤ longitude ≤ 103°W, 36°N ≤ latitude ≤ 39°N with a grid spacing of 2' 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 XGM2016 global geopotential model up to degree/order 719 is used. Integration radius for Stokes integral is chosen as 0.5°. The error degree variance of gravity anomalies is constructed using a bandlimited white noise model where standard deviation is taken as 3 mGal. The input gravity data include terrestrial and airborne data combined using 3D Least-Squares Collocation (LSC). The accuracy of the quasi-geoid model over GSVS17 GPS/leveling is 2.7 cm. The quasi-geoid model is provided in ISG format 2.0 (ISG Format Specifications), while the file in its original data format is available at the model ISG webpage.