###### Abstract
This presents an opportunity for the allocation of time slices to perception tasks [23]. Orthogonal Frequency Division Multiplexing (OFDM) waveforms are widely recognized as a common signal form in communication systems. They are characterized by strong multipath fading resilience, high frequency spectrum utilization, and other advantages that ensure optimal communication speed [6; 24]. Furthermore, the ambiguity function of OFDM is highly desirable, exhibiting a significant degree of flexibility in the allocation of time and frequency resources, which enables effective radar target detection [25; 26; 27]. The operational mode of a communication system typically involves the transmission of signals from one CBS, followed by their reception by another [28]. This operational mode closely resembles the working principle of Ground-Based SAR (GB-SAR) [29]. Consequently, a CBS can be utilized as a GB-SAR system in conjunction with interferometric measurement techniques to monitor millimeter-level ground deformation. It is undeniable that ground deformation monitoring can effectively predict geological disasters, such as landslides, debris flow, and collapses (which are typically accompanied by slight surface deformations or displacements prior to their occurrence), thereby reducing or avoiding damage to human life and property, which underscores its significant practical importance [30; 31]. Traditional methods of millimeter-level deformation monitoring, such as leveling and global Navigation Satellite Systems (GNSS), primarily observe pre-deployed target points to obtain information on deformation variables, deformation trends, etc. However, these conventional methods exhibit considerable limitations, including the ability to only capture deformation at monitoring points, high costs, and difficulties in deploying monitoring points [32; 33; 34]. Satellite-based Differential Interferometric SAR (D-InSAR) offers the advantage of wide-area coverage; however, its long revisit periods make it highly susceptible to atmospheric effects, orbital errors, and other influences, limiting its practical applications. To mitigate these challenges, the more widely adopted technique is Permanent Scatterer Interferometry (PSI) [35]. However, for scenarios with rapid deformation rates, the longer revisit periods of satellite-based InSAR render it challenging to accomplish high temporal resolution observations. In contrast, GB-SAR can perform multiple observations of the monitoring scene each hour (the specific frequency depending on the type of GB-SAR system used), effectively monitor ground deformation, and facilitate disaster prevention in such regions [36]. Over the past few decades, GB-SAR has been successfully applied in monitoring ground deformation in areas with landslides and mining subsidence, demonstrating high reliability and sensitivity [37; 38; 39; 40; 41]. Nevertheless, the development of GB-SAR in China has been relatively late, with most ground radar systems available for interferometric measurements still in the laboratory stage [42]. Currently, many deformation monitoring efforts rely on foreign equipment, which is costly and poses challenges for comprehensive deformation monitoring. By integrating ISAC technology, CBSs can be utilized as GB-SAR systems for millimeter-level deformation monitoring, thereby effectively addressing the limitations of current monitoring methods. Compared to satellite-based InSAR, a CBS exhibits a significant advantage in high temporal sampling rates. In relation to GB-SAR, a CBS is characterized by its low cost and extensive deployment capabilities. Given the extensive number of CBSs and their widespread distribution, high-density monitoring capabilities can be provided, enabling real-time observation of subtle ground deformations and significantly enhancing both the coverage and accuracy of monitoring efforts [43]. In this study, the feasibility of utilizing a CBS as a GB-SAR system for millimeter-level ground deformation detection is investigated for the first time.