由于地球同步轨道 (GEO)的衰减周期长，累积效应突出，空间碎片对卫星安全产生日益严重的威胁，特别是地基设备无法观测的危险空间碎片。根据碎片分布与运动特性，开展地球同步轨道星载太赫兹雷达碎片预警技术研究。针对工作波长、目标尺寸与雷达截面积 (RCS)、观测范围与工作方式进行论证，完成雷达系统方案和仿真分析。雷达采用有源相控阵天线，天线尺寸为250 mm×250 mm，工作频率为 140 GHz，平均功率为 190 W。雷达能够在方位与俯仰 ±15°、距离为1.95~24.12 km内搜索与跟踪尺寸为 6.8 mm~15 cm的碎片，并对将要产生的撞击进行预警，预警时 间4~35 s。

Due to the long decay period, space debris in Geosynchronous Earth Orbit(GEO) continue to accumulate, and threaten the safety of spacecraft, especially the dangerous debris which cannot be observed from ground based instruments. According to the distribution and motion characteristics of debris, a space based terahertz radar for debris approach warning is studied. Radar Cross Section(RCS)， wavelength, detection range and working process of the radar system are studied. Design and simulation results are presented. The radar carried by a geosynchronous earth orbit satellite utilizes an active phasedarray of the size 250 mm×250 mm， with working frequency of 140 GHz and average power consumption of 190 W. The radar can search and track debris of diameter 6.8 mm-15 cm in the cone of azimuth±15°, pitching±15°, and the range of 1.95-24.12 km, and can warn the spacecraft at least 4-35 s before the collision happens.