Research On Earth Rotation Parameters Of GNSS/VLBI/SLR Multi-source Data Fusion Epoch Reference Frame

Terrestrial reference frame is an implementation of the Earth Reference System and consists of a series of physical points of precisely known position and velocity under the corresponding Earth Reference System.This series of compatible coordinates and their evolution over time actually implies definitions.The origin,scale,orientation,and evolution over time of an Earth reference system.The most accurate and wide-ranging reference frame used worldwide is the International Reference Framework(ITRF)published by the International Earth Rotation and Reference System Service(IERS).The Earth Orientation Parameter(EOP)is a quantitative parameter that reflects the spatial motion of the Earth's rotation axis,the motion of the body,and the rate of rotation of the Earth.It is also the conversion parameter that links the celestial reference frame and the Earth reference frame,and describes the UT1 that describes the change in the Earth's rotation speed.The polar polar coordinates(Xp,Yp)describing the polar shift are called the Earth Rotation Parameters(ERP).With the development of space geodetic technology,technologies such as GNSS,SLR,VLBI,LLR,and DORIS can be used to locate and orbit,determine some of the reference parameters of the reference frame,or determine the Earth's rotation parameters.Since each technology has its advantages and disadvantages,it is impossible to measure all the benchmark parameters or the earth's rotation parameters through one technique.At present,there is no precedent for constructing a reference frame using a variety of spatial geodetic techniques.In this paper,the GNSS,SLR,VLBI technology SINEX file is used as the input data to reconstruct the unconstrained equations to realize multi-source data combination and solve the station coordinates and ERP parameters at the same time,and construct a multi-technology epoch reference frame.The following are the main research contents and results of this paper.1.Analysis of the current status of the Earth reference frame and the Earth's rotation parameters,and the principles and advantages and disadvantages of modern multi-space geodetic techniques in determining the Earth's reference frame and the Earth's rotation parameters,and choosing the multi-technology fusion solution for each technology application.prepare for;2.In-depth study of the theory and algorithm of spatial geodetic data fusion based on the equation of law,deducing the algorithm implemented by the epoch earth reference frame;studying the implementation method of the benchmark definition in the earth reference frame;3.Deduct in detail the algorithms combined in spatial geodetic techniques such as GNSS,SLR,VLBI,analyze the combined process,implement the intra-technology combination,and analyze the combined results;4.Analyze the combined model of spatial geodetic techniques such as GNSS,SLR and VLBI.The program realizes the combination of multi-technology solution calculation station coordinates and ERP parameters,establishes an epoch reference frame,and analyzes the combined results.5.Analyze the results of the fusion epoch reference frame,verify the accuracy of the multi-technology fusion reference frame by comparing the station coordinates and ERP parameters with single-technology data.