To compen- 19 sate for the omission errors in satellite-only GFMs, a spectral expansion approach is used to obtain 20 the refined gravity field models using the EGM2008 (Earth Gravitational Model 2008) and residual 21 terrain model (RTM) technique.
As a structural suggestion, considerable part of the Results are rather belong to Discussion (thus making the better balance between these two chapters, in extent and in content, too): I suggest point 3.3 (or maybe also 3.2) to Discussion – as they are discussing the already shown results. Conclusion – it shouldn’t be a summary as should be recompiled. The second part of the 3rd paragraph and the 4th paragraph are enough, completed by the estimated error of the main conclusive potantial value.