Abstract：In order to compare different time periods and different techniques for estimating earth rotation parameters, we design experiments to estimate ERP using CONT08, CONT11, CONT14, and CONT17 campaigns and IVS-R1/R4 regular observations in 2008, 2011, 2014 and 2017. At the same time, we use GPS data in the same period with CONT observations to participate in the solution. We use the EOP14 C04 sequence provided by IERS as a reference value for accuracy assessment. The results show that CONT17 has a higher polar motion solution accuracy than the other three sets of CONT observations, with an accuracy improvement of about 40%, but the accuracy of UT1-UTC is basically at the same level. CONT observations have more outstanding advantages than other types of VLBI observations, for example, the improvement in polar motion accuracy is about 30% and improvement in UT1-UTC accuracy is about 45%. As for the comparison between VLBI and GPS observations, the former is more advantageous in solving UT1-UTC, while the latter is more advantageous in estimating polar motion.
