Estimation Of Earth Rotation Parameters Based On The Combination Of VLBI And GNSS Technologies And Its Software Realization

The earth orientation parameters(EOP)including the earth rotation parameters(ERP)and nutation parameters.The high precision EOP is a key factor in establishing and maintaining the Terrestrial Reference Frame,realizing mutual conversion between ITRS and GCRS,satellite and deep space probe precise orbit determination and navigation.Very long baseline interferometry(VLBI)and global navigation satellite technology(GNSS)are the representatives of geometry and dynamics in space geodesy respectively,and they have advantages in solving the earth rotation parameters.VLBI plays an irreplaceable role in solving the EOP and maintaining the Terrestrial Reference Frame with its high accuracy and stability.However,the global stations are few and the observations are discontinuous because of its huge and expensive equipment.GNSS technology enables high-accuracy continuous observation throughout the day,and the global stations are evenly distributed.Sufficient high-precision observation data compensates for the discontinuity in the VLBI,but its stability has yet to be improved.Therefore,based on the SINEX files of VLBI and GNSS,this paper jointly solves ERP,exerts the advantages of each of the two space technologies,learns from each other,and improves the accuracy of the calculation of the earth's rotation parameters.This article mainly carried out the following work:1 The principles and formulas for solving the earth rotation parameters using GNSS and VLBI,and combination GNSS and VLBI based on their SINEX file for solving the earth rotation parameters are introduced and deduced in detail,and some key technologies in the fusion process of GNSS and VLBI are discussed.It lays a solid foundation for the subsequent software of combing solving ERP.2 Using the software of VLBI data processing to process and analyze the VLBI observation data of nearly ten years(2007-2016),obtain the high precision ERP and the standard SINEX solution files,and prepare the data for the subsequent use of the SINEX file of VLBI and GNSS for the combing calculation of ERP.And the VLBI data during CONT are high frequency calculation and analyzed,the short period term of pole shift parameters was explored.3 The data of CONT17 and July 2015 to December are experimentally analyzed by the software of combined VLBI and GNSS to solve ERP.The results show that the calculation accuracy of ERP is improved by combining GNSS and VLBI,and the reliability and stability of the combing VLBI and GNSS to solve ERP software are verified.