## 5 Conclusions  
A set of improved orbit solutions covering a period of more than a year was generated for the HY-2B satellite using a refined dynamic modeling and processing strategy. Key enhancements focused on a refined PEA strategy, GPS receiver offset calibration, and the implementation of integer ambiguity resolution. Updates to each processing strategy resulted in varying degrees of improvement for the orbit. Normally, PEA is used to absorb the uncertainties of physical modelling. To better understand the time-varying residual acceleration of spacecraft, here, we presented a refined PEA model. A spectral analysis was conducted to identify the potential periodicity of empirical acceleration in the HY-2B POD, and the main signals existing in the three dimensions (along-track, cross-track, and radial direction) were extracted and analyzed. The 4 CPR signal in the along-track direction and the 2 CPR in the radial direction were identified, and a mixed spectrum was observed for the cross-track direction. The three reprocessing strategies were applied to select an orbit solution of high quality. In the SLR validation, the refined PEA model with 4 CPR periodic acceleration in the along-track direction and 1 CPR periodic acceleration in the cross-track direction allowed a comprehensive strategy that could deal well with the mixed spectrum in the cross-track direction. Compared with regular strategies, a noticeable improvement in the SLR residuals for high-grade SLR stations was possible for orbits using the refined PEA strategy, which is still suggested as an ideal strategy for empirical acceleration modeling. Estimation of the PCO and modeling of the PCV can effectively eliminate the systematic deviation related to signal incidence and significantly reduce the phase residuals. A systematic bias of 20 mm for the HY-2B GPS antenna phase center could be observed. Based on the PCO's z-component time series of more than 1 year, a decreasing trend appeared in this direction. For 11 high-performance SLR sites, SLR residuals with a standard deviation as low as 15.7 mm were obtained for the HY-2B POD, which produced a 25% improvement compared with the solution without PCO/PCV. Ambiguity resolution added a strong constrained geometry for other estimation parameters in POD, and better orbit precision (13.3 mm RMS) was confirmed by independent SLR measurements. Some studies related to ours are available [13; 16; 53]. The lean set of auxiliary data from the CNES/CLS products will be attractive for the wider LEO POD community. Conceptualization, Y.W. and M.L. ([PERSON]); methodology, Y.W. and K.J. ; software, M.L. ([PERSON]) and Q.Z. ; validation, K.J., W.L. and G.Q. ; formal analysis, M.L. ([PERSON]); investigation, Y.W. and K.J. ; resources, H.P. and M.L. ([PERSON]); data curation, Y.W. and M.L. ([PERSON]); writing--original draft preparation, Y.W. ; writing--review and editing, M.L. ([PERSON]); visualization, Y.W. ; supervision, M.L. ([PERSON]); project administration, M.L. ([PERSON]) and H.P. ; funding acquisi-tion, M.L. ([PERSON]). All authors have read and agreed to the published version of the manuscript. This study was supported by the National Natural Science Foundation of China (Grant Nos. 42074032, 41931075, 42030109 and 42004020) and the Wuhan Science and Technology Bureau (2019010701011391). Data Availability Statement: The GNSS precise orbit and clock products are publicly available from [[ftp://igs.gnsswhu.cn/pub/gnss/products/mgex/](ftp://igs.gnsswhu.cn/pub/gnss/products/mgex/)]([ftp://igs.gnsswhu.cn/pub/gnss/products/mgex/](ftp://igs.gnsswhu.cn/pub/gnss/products/mgex/)) (accessed on 1 August 2021). The SLR observations of HY-2B is provided by ILRS at [[ftp://cddis.gsfc.nasa.gov/pub/slr/data/](ftp://cddis.gsfc.nasa.gov/pub/slr/data/)]([ftp://cddis.gsfc.nasa.gov/pub/slr/data/](ftp://cddis.gsfc.nasa.gov/pub/slr/data/)) (accessed on 1 August 2021).