## 7 Conclusions
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Solution**} & \multicolumn{2}{c}{**Xp [\(\mu\)as]**} & \multicolumn{2}{c}{**Yp [\(\mu\)as]**} & \multicolumn{2}{c}{**LOD [\(\mu\)s/d]**} & \multicolumn{2}{c}{**Xrt [\(\mu\)as/d]**} & \multicolumn{2}{c}{**Yrt [\(\mu\)as/d]**} \\ \cline{2-11}  & **Mean** & **STD** & **Mean** & **STD** & **Mean** & **STD** & **Mean** & **STD** & **Mean** & **STD** \\ \hline
1-day arc & & & & & & & & & & \\ \hline B1I/B3I & 12 & 93 & \(-94\) & 84 & \(-4.8\) & 31.1 & \(-166\) & 367 & \(-253\) & 551 \\ BIC/B2a & \(-62\) & 114 & \(-19\) & 75 & 1.8 & 31.8 & \(-212\) & 372 & \(-332\) & 574 \\ GPS & \(-4\) & 51 & 29 & 66 & 6.7 & 19.4 & \(-160\) & 214 & \(-73\) & 213 \\ \hline
3-day arc & & & & & & & & & \\ \hline B1I/B3I & 109 & 65 & \(-41\) & 48 & 5.2 & 22.2 & 28 & 131 & 14 & 104 \\ BIC/B2a & 48 & 63 & 19 & 47 & 4.0 & 22.0 & 17 & 123 & 5 & 101 \\ GPS & \(-3\) & 32 & 17 & 25 & 7.1 & 18.9 & 1 & 120 & 3 & 97 \\ \hline \hline \end{tabular}
\end{table} 
Table 11: The mean offsets and STD of ERP differences with reference to IERS 20C04 products for BDS-3 B1I/B3I solutions, B1C/B2a solutions, and GPS solutions. The utilization of the BDS-3 B1C/B2a combination leads to a noteworthy improvement, with mean differences reduced by 56% for X PM, 54% for Y PM, 39% for the X PM rate, 64% for the Y PM rate, and 23% for LOD, in comparison with B1I/B3I. In the aspect of STD, the outcomes for the 3-day arc ERP estimates from the BDS-3 B1C/B2a combination are as follows: 63 uas for X PM and 47 uas for Y PM, 123 uas/d for the X PM rate, 101 uas/d for the Y PM rate, and 22.0 uS/d for LOD. The B1C/B2a solutions result in STDs of residuals that are approximately 3% for X PM, 2% for Y PM, 1% for X PM rate, 6% for Y PM rate, and 3% for LOD, better than the B1I/B3I solutions. Therefore, the results demonstrate the excellent signal quality for the BDS-3 B1C/B2a and its superiority in the ERP estimation when comparing with the B1 IBS3I combination. Since the number and distribution of MGEX stations supporting B1C/B2a signals tracking are inferior to the B1I/B3I tracking stations, the performance of ERP derived from BDS-3 B1C/B2a signals maybe better with more global MGEX stations supporting BDS-3 B1C/B2a signals tracking in the future or adding Low Earth Orbit satellite observations. [PERSON] and [PERSON] proposed the idea of this study. [PERSON] performed the experiments and analyzed the data. [PERSON], [PERSON] and [PERSON] discussed the results. [PERSON] and [PERSON] prepared the original manuscript. [PERSON], [PERSON] and [PERSON] developed and modified the software. All authors have read and agreed to the published version of the manuscript. This research was supported by the National Natural Science Foundation of China (Grant No. 42388102 and No. 42204015), the China Post-doctoral Science Foundation (2023M732041), Youth Innovation Team Development Project of Higher School in Shandong Province (2023 KJ143), and the Young Scholars Program of Shandong University, Weihai. In this study, the GNSS observation data can be downloaded from [[https://cddis.nasa.gov/archive/gps/data/daily/](https://cddis.nasa.gov/archive/gps/data/daily/)]([https://cddis.nasa.gov/archive/gps/data/daily/](https://cddis.nasa.gov/archive/gps/data/daily/)) (accessed on 25 February 2024), the CODE MGEX products are available at [[http://ftp.aiub.unibe.ch/CODE_MGEX/CODE/](http://ftp.aiub.unibe.ch/CODE_MGEX/CODE/)]([http://ftp.aiub.unibe.ch/CODE_MGEX/CODE/](http://ftp.aiub.unibe.ch/CODE_MGEX/CODE/)) (accessed on 25 February 2024), the SLR observation data can be found at [[https://cddis.nasa.gov/archive/slr/data/](https://cddis.nasa.gov/archive/slr/data/)]([https://cddis.nasa.gov/archive/slr/data/](https://cddis.nasa.gov/archive/slr/data/)) (accessed on 25 February 2024), and the IERS 20C04 products are available at [[https://hpiers.obspm.fr/iers/eop/eopc04/](https://hpiers.obspm.fr/iers/eop/eopc04/)]([https://hpiers.obspm.fr/iers/eop/eopc04/](https://hpiers.obspm.fr/iers/eop/eopc04/)) (accessed on 25 February 2024).