In this study, commercial (GAMMA) and free [Stanford method for persistent scatterers (StaMPS)] analysis tools, along with synthetic aperture radar (SAR) data of different resolutions, were compared using the interferometry synthetic aperture radar (InSAR) technique to monitor ground displacement at an environmental infrastructure facility site in southeastern Korea. Persistent scatterer interferometry SAR (PSInSAR) analysis was performed using SAR data from Sentinel-1, a representative satellite operating at the C-band frequency, and TanDEM-X, which provides X-band frequency data. The two tools showed similar trends, with root mean squared deviation values of 1–4 mm in areas containing artificial structures. However, differences emerged depending on data resolution and properties in areas with low signal interference, such as large and flat environmental infrastructure sites. The TanDEM-X high- resolution X-band data exhibited a higher reliability than the Sentinel-1 data, confirming their suitability for displacement detection in facilities such as waste landfills. Furthermore, because the StaMPS software has limitations in selecting persistent scatterers, the GAMMA-based results were more stable. These findings highlight the need to simultaneously employ high-resolution SAR data and highly reliable analysis tools for accurate surface displacement monitoring in vulnerable areas, such as waste landfills, and demonstrate the applicability and limitations of SAR-based displacement monitoring in similar environments.