一种基于时间调制的弹性化SAR卫星系统

星载合成孔径雷达(SAR)系统能全天时、全天候观测,在地震、洪涝、台风等自然灾害监测中具有重要作用。双基、多基SAR卫星更具有极高的经济、科学、安全价值。然而,目前在轨的大型星载SAR卫星造价昂贵,且双基SAR卫星需数颗同等规模的卫星。双基SAR卫星系统存在星间同步链路,因此卫星可扩展性不强。提出了一种基于时间调制的低成本弹性化Ka波段调频连续波(FMCW)SAR小卫星星座系统。该系统基于一组独立、模块化的发射卫星和接收卫星。采用Ka FMCW SAR体制和时间调制天线(TMA)技术,可减轻接收星2/3以上的质量。该系统采用自主任务规划技术,具备多样化的工作模式,为单发多收、多发多收等应用需求提供了一种弹性化的解决方案。

A Novel Expandable SAR Satellite System Based on Time Modulated Antenna

The space-borne synthetic aperture radar (SAR) system is playing an important role, with all weather and all time observation capability, in monitoring earthquake, flood, typhoon and other nature disasters. Bistatic and multistatic SAR systems proposed recently also have a high potential for scientific, commercial and security applications. However, the cost of large SAR satellites in orbit is tremendously high. Bistatic system usually needs several identical satellites. On account of the synchronization link, the system is lack of expandability. Therefore, this paper introduces the concept of a novel low-cost microsatellite system based on Ka-band frequency modulated continuous wave (FMCW) SAR system. It is composed of a set of mutually separated transmitter and receiver satellites. By adopting FMCW SAR and time modulated antenna (TMA) concept, mass and cost of the satellite will be significantly reduced. With autonomous task planning, this system can possess diversified observation modes, providing an expandable solution for single-input single-output (SISO) mode, single-input multiple-output (SIMO) mode or even multiple-input multiple-output (MIMO) mode.