Modeling and Analysis of the Impacts of Temporal-Spatial Variant Troposphere on Ground-Based SAR Imaging of Asteroids  

作　　者：Tingting Fu Yuanhao Li Zhiyang Chen Zheng Wu Cheng Hu 

机构地区：[1]Radar Research Laboratory,School of Information and Electronics,Beijing Institute of Technology,Beijing 100081,China [2]Beijing Key Laboratory of Embedded Real-time Information Processing Technology [3]the Chongqing Institute of Meteorological Sciences,Chongqing 401147,China

出　　处：《Journal of Beijing Institute of Technology》2023年第6期727-739,共13页北京理工大学学报（英文版）

基　　金：supported in part by the National Natural Science Foundation of China(Nos.62101039,62201051);in part by the Shandong Excellent Young Scientists Fund Program(Overseas);in part by China Postdoctoral Science Foundation(No.2022M720443).

摘　　要：The near-Earth asteroid collisions could cause catastrophic disasters to humanity and the Earth,so it is crucial to monitor asteroids.Ground-based synthetic aperture radar(SAR)is an observation technique for high resolution imaging of asteroids.The ground-based SAR requires a long integration time to achieve a large synthetic aperture,and the echo signal will be seriously affected by temporal-spatial variant troposphere.Traditional spatiotemporal freezing tropospheric models are ineffective.To cope with this,this paper models and analyses the impacts of temporal-spatial variant troposphere on ground-based SAR imaging of asteroids.For the background tropo-sphere,a temporal-spatial variant ray tracing method is proposed to trace the 4D(3D spatial+temporal)refractive index network provided by the numerical weather model,and calculate the error of the background troposphere.For the tropospheric turbulence,the Andrew power spectral model is used in conjunction with multiphase screen theory,and varying errors are obtained by tracking the changing position of the pierce point on the phase screen.Through simulation,the impact of temporal-spatial variant tropospheric errors on image quality is analyzed,and the simulation results show that the X-band echo signal is seriously affected by the troposphere and the echo signal must be compensated.

关 键 词：near-Earth asteroids ground-based SAR troposphere ray tracing 

分 类 号：TN957.52[电子电信—信号与信息处理]