The argumentation on avoiding adopted atmospheric distributing model in refraction delay model

The astronomical atmospheric refraction is an error source in classical astrometry and geodesy.The refraction delay is a very important error source in techniques of space geodesy.Their correction models are directly related to the atmospheric refractive index and the atmosphere distribution model.This paper simply reviews the circs of atmosphere upright distributing,as well as the status of atmospheric index or refractivity that be different with the station and azimuth,and analyzes the reason why can we adopt spherical symmetry atmosphere model at present.At the same time,it demonstrates the feasibility and necessity to construct the surveying model according to different station and azimuth,which can survey astronomical atmosphere refraction and refraction delay of electromagnetic wave.Because the surveying model has considered the actual distribution of atmosphere above station and the characteristic of non-sphere symmetry of atmosphere,it isn't necessary to searching or constituting the atmosphere distribution model according to topography and season.The surveying model has avoided the effect of unsuitable atmosphere model.Consequently,it excluded an important error source in space geodesy.