大偏心率小倾角GEO SAR观测特性及成像研究

Observational Properties and Imaging Analysis for Geosynchronous SAR of High Eccentricity and Nearly Zero Inclination

地球同步轨道合成孔径雷达(Geosynchronous Earth Orbital Synthetic Aperture Radar,GEO SAR)具有重访周期短,观测区域大等优势,可以对大面积热点区域进行长时间连续观测,在军事侦察、土壤湿度和自然灾害监测等领域具有重要应用前景。当前GEO SAR研究主要集中在大倾角小偏心率轨道,而关于大偏心率小倾角则鲜有涉及。因此针对大偏心率小倾角GEO SAR的观测特性问题,仿真了卫星在不同轨道配置下的空间轨迹及覆盖性能示意图,说明了其观测性能优势,并仿真了此时“走-停”假设误差的大小,使用后向投影(Back Projection,BP)算法给出了卫星在不同轨道位置处的聚焦成像结果,说明成像算法的有效性。

Geosynchronous Earth Orbital Synthetic Aperture Radar(GEO S A R)has the attractive advantages such as daily revisit period as well as extensive coverage,which can be used for long time and consistently observing of hotspots with large areas,thus this can be positively predicted in military investigation,soil moisture and natural disaster monitoring management applications.Current GEO SAR research focuses mainly on big inclination with low eccentricity orbit,while the study on nearly zero inclination with high eccentricity orbit is rarely involved.Thus,ai ming at the observational characteristics in this orbits,space trajectory and coverage performance has been simulated to illustrate that the hotspots can be continuous observed for 24 hours in high eccentricity and nearly zero inclination orbit configuration.Then,we simulated the errors of“Stop-Go”assumption and finally show the focused images of different orbital positions by back projection algorithm to illustrate its efficiency.