Accuracy Analysis Of Atlas Based On Satellite Based Wide Area Differential System

As the important part of GNSS system,wide area differential enhanced SBAS system plays a more and more important role in the fields of military,resource exploration,navigation and communication and so on.In order to develop the satellite navigation industry of our own country,to get rid of the foreign dependence,to break the international augmentation system technology blockade and monopoly prices,the country have also established their own satellite based wide area differential enhancement system.As a new SBAS system,it is necessary to carry out further verification through the experiment to proving what the specific level of positioning can be achieved,especially in the Guizhou mountain terrain environment conditions.The article focuses on the positioning accuracy of the study,the main contents are as follows:1?This paper introduces the background of the SBAS system,expounds the connotation of the SBAS system,and briefly introduces the composition and structural characteristics of the popular SBAS system in the world.2?This paper briefly introduces the system composition and related index parameters of the new SBAS system which is put into use in China,and gives a brief description of its positioning principle,and puts forward the experimental principle and the way to verify the accuracy of the Atlas system.3?The positioning accuracy of the Atlas system is verified by the location of the experimentation area and different coordinate systems.According to the experimental data,it is known that the positioning deviation is large,no positioning accuracy at all when using the Guiyang independent coordinate system,Beijing 54 coordinate system and Xi'an 80 coordinate system.But when using the CGCS2000 coordinate system,the plane positioning accuracy is in the sub-meter level,the average positioning accuracy is about 30 cm,the height positioning accuracy is uniform deviation 30 m,and analysis of possible reasons.4?In view of the results of stand-alone positioning,it is proposed to improve the positioning accuracy by introducing a known point correction method.In the experiment,the positioning accuracy is improved from the number of control points and the control point distribution,and verifies the accuracy difference in different modes.Through the experiment we can know that in the experimentation area of Guiyang,respectively into one,two or three known control points or the same number of control points in different points of distribution,the result data no significant difference between the positioning accuracy,in addition to individual point abnormal,the overall positioning accuracy is about 10cm;The distribution of the whole experimentation area of Anshun and the control points are linear,the experimental data show that the positioning error of different number of control points is less than 20 cm,and the influence of different point distribution on the positioning accuracy is very small,the overall positioning accuracy of the experimentation area is about 17cm;The positioning accuracy deviation between the two experimentation area was about 7cm,and analysis the possible reasons.5?The experiments are also verify the characteristics of the Atlas system by the way of multi-period positioning,the existing engineering experiments and the different baseline distance.The experimental data show that the positioning accuracy of the multi-period consistent with the first experiment;The experimental positioning accuracy of engineering file retest are same as the original experimental;And with the increase of baseline distance,the positioning accuracy decreased gradually.