## 1 Introduction
[14] employed a coherence-optimized SBAS approach using ascending and descending Sentinel-1A data in conjunction with descending high-resolution TerraSAR-X imagery. This approach enabled the millimeter-level monitoring of slope deformation in the Rhenish open-pit mine in Germany, facilitating the retrieval of surface displacement within and around the mining area and supporting a detailed analysisof the deformation mechanisms. [PERSON] et al. [15] proposed an enhanced Stacking-InSAR technique that integrated coherence gradient analysis, leveraging GF-3 and Sentinel-1 data to monitor large-scale mining subsidence while addressing challenges such as decorrelation and displacement underestimation in regions with steep deformation gradients. Although high-resolution SAR images have greatly enhanced our capabilities in mining-related deformation monitoring, the widespread application of international high-resolution satellites such as TerraSAR-X is hindered by high acquisition costs and region-specific imaging priorities, which limit continuous data availability for some areas of China. While the launch of GF-3, China's first C-band high-resolution SAR satellite, fills the domestic data gap, it is mainly used for national security due to regulatory constraints. Civilian use requires lengthy, strict approval. While medium-to-low-resolution data such as Sentinel-1 can serve as a partial substitute, their limited spatial resolution and precision limit their utility in high-accuracy monitoring tasks, impeding their use both in scientific research and in practical applications in mining deformation monitoring. The Chinese commercial small satellite industry is experiencing rapid growth [16], with significant advancements in small SAR satellites. These satellites have become a focal point for strategic competition among emerging aerospace enterprises. Representative examples include the \"Fucheng-1\" and \"Shenqi\" dual-satellite constellation, developed by the Changsha Tianyi Research Institute, which was launched successfully and has been in operation for several years. These platforms have consistently acquired large volumes of high-quality SAR datasets, showing marked improvements in SAR interferometry performance and capabilities in the Chinese commercial SAR sector [17]. Characterized by a high resolution, low cost, and rapid response, small SAR satellites are well suited for applications including disaster monitoring, urban planning, agricultural assessment, and maritime law enforcement. Additionally, the strict orbit control demands faced by dual-star constellations significantly challenge the Flight Operations Center, especially the Flight Dynamics System. Depending on solar and geomagnetic activity, frequent weekly maneuvers may be required. Flight Dynamics must monitor ground track evolution daily, often outside normal hours, and generate maneuver execution products 2-5 times weekly, with adequate uplink opportunities for timely satellite updates [18]. Despite these technological advancements and challenges, there is still a lack of Chinese case studies utilizing small-satellite SAR data to monitor geological deformation in mining areas. To address this gap, in this study, we employed TS-InSAR technology to monitor surface deformation in complex open-pit mining environments using high-resolution SAR imagery from the \"Fucheng-1\" and \"Shenqi\" satellites. Specifically, we analyzed ground deformation in the Jinchuan mining area, Gansu Province, using 15 scenes with high-resolution images from the \"Fucheng-1\" satellite and 5 scenes from the \"Shenqi\" satellite with PS-InSAR technology. The results were compared with, and validated using, those obtained from both PS-InSAR and DS-InSAR using Sentinel-1A data. Corner reflectors (CRs) installed within the mining area helped in evaluating the reliability of the InSAR results. This study demonstrates the effectiveness of using \"Fucheng-1\" and \"Shenqi\" satellite data in monitoring rapid subsidence caused by mining activities.