## 4 The Deformation Detection Experiment and Results
### Comparison with Traditional Deformation Monitoring Methods  
The integration of CBSs with D-InSAR technology provides a novel observational approach for ground deformation detection, significantly impacting both radar remote sensing and deformation monitoring fields. When comparing CBSs to traditional satellite SAR platforms and GB-SAR platforms, several key aspects emerge.  
Cost: The design, launch, and maintenance of satellite SAR platforms require substantial financial investment. While GB-SAR platforms are less costly than satellite SAR platforms, their construction and maintenance still entail significant expenditure. In contrast, the extensive deployment of CBSs can effectively reduce the overall costs associated with radar system implementation.  
Flexibility and Scalability: Satellite SAR platforms operate on fixed orbits, making it challenging to adapt to various observational tasks. Similarly, once GB-SAR platforms are established, their observation areas become fixed, limiting scheduling flexibility. CBSs, being densely distributed, allow for dynamic selection of observation areas and targets based on demand. Furthermore, cooperative observations among multiple CBSs represent an important future research direction. These CBSs can also simultaneously support communication and radar detection tasks, facilitating efficient resource utilization.  
Temporal Sampling Rate: Due to its fixed orbital path, satellite SAR platforms exhibit longer revisit periods (typically at least several days), resulting in the lowest temporal sampling rate. In contrast, the time interval between successive observations in GB-SAR platforms can reach several seconds, while CBSs can achieve millisecond-level observation intervals. Furthermore, the observation time interval is closely related to temporal decorrelation. Consequently, the temporal decorrelation is most severe in satellite SAR platforms, while it is least pronounced in CBSs.  
Observation Range and Accuracy: Satellite SAR platforms benefit from their orbital advantages, enabling wide-area observations, which is a capability difficult to achieve with GB-SAR platforms and CBSs. However, satellite SAR platforms are susceptible to significant atmospheric interference, necessitating complex correction algorithms to meet high accuracy requirements. Conversely, GB-SAR platforms and CBSs experience reduced atmospheric effects due to their shorter observation distances, resulting in higher deformation monitoring accuracy. However, this proximity also limits the observational range of GB-SAR platforms and CBSs.  
The preceding paragraphs provide a detailed comparison of several key characteristics of CBSs in relation to traditional deformation monitoring methods. To facilitate a more intuitive understanding of the differences between these characteristics for the reader, Table 4 presents a summarized comparison.  
In summary, the combination of CBSs with D-InSAR technology presents a compelling alternative for ground deformation monitoring. Consequently, the application of CBSs for ground deformation monitoring holds significant practical importance in mitigating the risks posed by natural disasters and addressing potential threats to urban infrastructure.