Ludi Tance-1 is China’s first satellite formation system for deformation measurement and monitoring with differential interferometry SAR technology. As a part of the twin satellites for land-observation, the L-SAR 01B satellite was sent into a sun-synchronous orbit on 27th Feb, 2022 at 7:44 a.m., to jointly explore the earth with L-SAR 01A. Shanghai Jiao Tong University served as the deputy chief design engineering department and developed the core technology of satellite formation to guarantee the precision measured in millimetres for Ludi Tance-1.

As the first launched satellite following China’s National development plan of Medium and Long-Term Development Strategy of China’s civil Space Infrastructure, Ludi Tance-1 satellite, together with the twin satellite, has demonstrated its potential as repeat-pass differential interferometric deformation measurement and topographic mapping tools, which used a brand-new formation technology developed by Shanghai Jiao Tong University. The Ludi Tance satellites facilitate land mapping and resource monitoring to help the government give a quicker respond to all kinds of major events and geological disasters such as earthquakes and landslides. China heavily relies on foreign countries to attain SAR data, but now with the competitive Ludi Tance-1, we can change the situation.

Shao Xiaowei, the research fellow of the School of Aeronautics and Astronautics, Shanghai Jiao Tong University, serves as the deputy chief designer of Ludi Tance-1 satellite. His group mainly designed the satellite formation configuration, frozen repeat orbit pattern, and mission planning and scheduling. They were also responsible for evaluating the baseline performance of the satellite height-measurement and deformation-monitoring before the lift-off. Their work secures a repetitive monitoring technology with 100m precision in land deformation and a long-term interference mapping tool in land observation. Chen Junli, the chief designer of Ludi Tance-1, has spoken highly of the contribution made by Shanghai Jiao Tong University. He said their research outcome lays a good foundation for developing SAR satellite and enables China to conduct more formation-based technological innovation.

So far, Shao Xiaowei and his group have proposed a scientific and complete theoretical framework for satellite formation system, meeting the requirements for national major technical equipment and projects in the area of distributed satellite system for microwave mapping. They have also made a lot of original research achievements on the on-orbit application of satellite formation which benefit the capture and process of satellite data.