## 3 Results
### Pilot Adjustment of Early Unified Control Points (2008-2010) for Strategy Validation  
To verify the reliability of the integrated adjustment strategy described in Section 3.1, a pilot adjustment was conducted prior to the nationwide application involving approximately 5560 unified control points (UCPs). This preliminary analysis targeted around 1200 UCPs installed between 2008 and 2010, distributed across diverse regions of South Korea, including Seoul, Gyeonggi, Gangwon, Chungnam, Gyeongsang, Jeolla, and Jeju. The pilot adjustment enabled technical validation of the adjustment methodology and consistency testing against previously published coordinate values. In the conventional approach, newly installed UCPs were adjusted using short-baseline network processing that connected them to four or five nearby continuously operating reference stations (CORS). The resulting coordinates were published under the Korean Geodetic Datum (KGD), referenced to ITRF2000 at epoch 2002.0. In contrast, the present study adopts a nationwide strategy using fixed CORS across the entire country and applies a unified adjustment framework referenced to ITRF2014 at epoch 2002.0. This pilot test serves as a reliability assessment for the integrated approach prior to applying the same methodology to all 5560 UCPs in Section 3.3. Baseline processing and network adjustment were carried out using GAMIT/GLOBK and Bernese software packages, depending on the year of UCP installation. Specifically, GAMIT/GLOBK was applied to UCPs established in 2008 and 2010, while Bernese was used for those installed in 2009. After excluding stations with incomplete observation logs, inconsistent metadata, or poor data quality, the final pilot network consisted of 1193 UCPs. To provide geodetic control, 41 continuously operating reference stations (CORS) were held fixed throughout the adjustment process. Table 5 summarizes the adjustment setup by year, and Figure 5 illustrates the annual distribution of the UCPs used in this pilot study. Figure 4: Location of selected domestic CORS in the Republic of Korea. The spatial structure of the pilot network and its baseline geometry are shown in Figure 6. The triangulated connections between UCPs demonstrate a dense and uniformly distributed geodetic framework, anchored by fixed CORS across the nation. The resulting baseline network highlights the strong spatial coherence of the integrated adjustment model. To evaluate the effectiveness of the integrated adjustment strategy, newly computed coordinates were compared with previously published values derived from year-by-year regional adjustments. These earlier adjustments were typically performed independently  
Figure 5: Spatial distribution of unified control points (UCPs) installed in 2008, 2009, and 2010. Red triangles represent fixed CORS used for each year’s adjustment. \begin{table}
\begin{tabular}{c c c c} \hline
**Year** & **Region (Example)** & **Adjustment Software** & **UCPs** \\ \hline
2008 & Seoul, Gyeonggi, Gangwon & GAMIT/GLOBK & \(\sim\)300 \\
2009 & Gyeongsang, Jeolla & Bernese & \(\sim\)600 \\
2010 & Gangwon, Jeju & GAMIT/GLOBK & \(\sim\)300 \\ \hline \end{tabular}
\end{table} 
Table 5: Summary of unified control points and adjustment setup for the pilot study. Figure 6: Integrated baseline network of 1193 unified control points installed between 2008 and 2010. Red triangles represent fixed CORS, and lines indicate triangulated baseline connections. within localized baseline networks and applied inconsistent stochastic constraints, often aligned with administrative boundaries or observational periods. This fragmented approach resulted in temporal and spatial discontinuities, and over time, such inconsistencies accumulated, leading to systematic distortions within the national geodetic coordinate framework. In contrast, the integrated adjustment method adopted in this study utilized a unified modeling framework, a consistent set of fixed stations, and harmonized stochastic assumptions across the entire network.