The VRS Technology Algorithm Research Based On GNSS

With the development of the Global Navigation Satellite System in science,military and commercial fields continuously.The application of high-precision Navigation and positioning is becoming more and more extensive.As a new generation of high-precision GNSS positioning technology,Network-RTK technology overcome the defects of the conventional RTK technology,widens the range of positioning,and the positioning result and reliability have been greatly improved.Virtual Reference Station technology is a kind of more mature Network RTK technology.VRS can provide real-time and high precision navigation and positioning information.The main advantages of VRS include wide coverage,high positioning accuracy and high reliability,which gradually become a hot spot in the research of precision positioning.This paper studies the VRS algorithm based on GNSS,include the following aspects:(1)First of all,this paper studies the integration theory of time system and coordinate system based on GPS/BDS.This paper mainly introduces the non-differential and double-difference positioning model of the fusion system,the satellite elevation Angle model,the tropospheric error correction model,the ionospheric error correction model,etc.(2)This paper introduces the basic theory of the Ambiguity resolution,especially the single epoch ambiguity resolution technology.In addition,this paper studies calculating method for the VRS ambiguity solution technology between reference station and ambiguity calculating method between reference station and rover.(3)The regional interpolation model of the base station network is studied in detail.It analyze that correction effect and precision of the atmospheric delay error such as ionosphere and troposphere of ionospheric and troposphere by the interpolation model in four regions of LCM algorithm,LIM algorithm,LSM algorithm and DIM algorithm.Select the most appropriate interpolation model to correct the error of the virtual reference station area.The observation value of virtual reference station is generated according to the correction information,which is used for the positioning calculation of the rover station.(4)The principle of VRS algorithm is introduced in detail.The VRS post-processing positioning program is developed by using the VRS algorithm.The measured data of the receiver is processed by the VRS post-processing positioning program.Analysis results in east and north direction positioning precision can reach 1?3 cm,accuracy is higher than 10 cm in height direction,overall shows the VRS algorithm based on GNSS technology can realize cm-level precision positioning.