“宏图一号”陕西省榆林市多基线干涉高精度数字表面模型图

封面图片为我国商业雷达遥感卫星 “宏图一号”获取的陕西省榆林市地区的多基线干涉高精度数字表面模型图，图中地形地貌纹理清晰，地表脉络清楚可见。“宏图一号”合成孔径雷达（SAR）系统由“一主三辅” 4 颗卫星形成车轮式干涉编队，是国际上首个星载单航过多基线干涉 SAR 系统，具备高分辨对地观测和多基线高精度、高效率干涉地形测绘能力。中国科学院空天信息创新研究院航天微波遥感系统部承担了 SAR 载荷、编队构型约束设计及多星空时频同步等系统设计开发与工程研制，突破了多星编队基线设计与优化、空时频高精度同步、多基线联合相位解缠及多基三维成像、载荷轻量化低成本等多项具有完全自主知识产权的核心关键技术。系统最高分辨率优于 0.5 m，具备 1:5 万比例尺测绘能力。

The high-precision Digital Surface Model (DSM) of partial area in Yulin city, Shaanxi Province by the "Hongtu-1" constellation multi-baseline InSAR measurement

The cover image shows a high-precision Digital Surface Model (DSM) of partial area in Yulin city, Shaanxi Province, obtained by China's commercial radar satellite constellation "Hongtu-1". The terrain and geomorphic texture in the image are clearly visible, and the surface veins are fully demonstrated. The Hongtu-1 Synthetic Aperture Radar (SAR) constellation consists of four satellites, one primary and three auxiliary satellites, forming an interferometric wheel formation. It is the first spaceborne single-pass multi-baseline interferometric SAR (InSAR) system in the world, with the capabilities of high-resolution earth observation and high-precision high-efficiency multi-baseline InSAR terrain mapping. The Department of Space Microwave Remote Sensing System, Aerospace Information Research Institute, Chinese Academy of Sciences (AIRCAS) has undertaken the design of formation configuration constraints, the design and engineering development of SAR payloads, and the inter-satellite space, time, phase synchronization systems. Multiple key technologies with independent intellectual property rights have been broken through, such as multi satellite baseline design and optimization, high-precision inter-satellite synchronization, multi-baseline phase unwrapping, multi-static three-dimensional imaging, lightweight and low-cost payload scheme. The highest resolution of the system is better than 0.5 m, and it has a 1:50000 scale surveying capability.