Application and Prospect of Lutan -1 SAR Satellite Constellation in Earthquake Industry

Objectives: Lutan-1 (LT-1), the first constellation of civil L-band interferometric SAR satellites in China, primarily focuses on surface deformation measurement by leveraging the differential interferometric, while also possessing height measurement and fully polarimetric imaging capabilities. With its dual-satellite information imaging mode, it can achieve a strict revisit period of four days, which is highly beneficial for surface deformation monitoring and emergency response to natural disasters such as earthquakes. From the perspective of the LT-1 SAR satellite's imaging capabilities and the demands of the seismic industry, this paper primarily highlights the preliminary applications of the satellite system during the testing phase. The main objective is to evaluate the satellite data's capabilities in co-seismic deformation monitoring, emergency observations, and remote sensing interpretation of active fault zones. The ultimate purpose is to provide a reference for the future commercialization of seismic applications, based on the potential applications of the satellite data in these fields. Methods: Taking the examples of the 2022 Luding earthquake(China),the 2023 Turkey earthquakes, and the Gansu earthquake(China), co-seismic deformation monitoring will be conducted. The deformation maps will be assessed in terms of accuracy and monitoring capabilities. Additionally, emergency assessments of secondary earthquake hazards and remote sensing investigations of active fault zones will be carried out based on the high-resolution SAR data from the LT-1 satellite. Results: By comparing the co-seismic deformation results derived from LT-1 satellites with the results from concurrent other SAR satellites and GNSS measurements, it has been verified that the LT-1 satellite has significant advantages in terms of monitoring accuracy and spatiotemporal resolution. In addition, leveraging the highresolution advantage of LT-1 SAR satellite imagery, it is possible to quickly obtain information on the distribution of earthquake-induced landslides and accurately delineate the accessibility of roads in the affected area. This capability effectively supports earthquake emergency response and disaster assessment efforts. Furthermore, thanks to the L-band sensor, the LT-1 satellite exhibits strong penetration capabilities, thus enabling the detection of hidden faults. Conclusions: Through multiple case studies in the seismic industry, encompassing various areas such as coseismic deformation monitoring, emergency response, and hidden fault detection, the results have demonstrated that the LT-1 satellite constellation has a significant breadth and depth of applications in the seismic industry. In the future, it will effectively support scientific research on seismic cycles and earthquake emergency operations.