GEO-UAV 双基SAR成像模型与处理方法研究

GEO-UAV BSAR is an innovative bistatic remote sensing system, in which the Geosynchronous SAR serves as the transmitter of opportunity, while the receiver is mounted on the UAV platform. GEO-UAV BSAR can be applied to obtain multi-perspective images of the interesting region with high temporal and spatial resolutions. It can also be able to achieve 3-D images when the UAV platform moves along curvilinear trajectories. GEO-UAV BSAR benefits from high operational flexibility, quick response, and reduced vulnerability to counter-measurement, consequently, is a promising technique with great potential. However, new technical challenges of information obtainment and processing for GEO-UAV BSAR need to be dealt with. Combing the theoretical research and the engineering application, this project focuses on two key issues of GEO-UAV BSAR: the imaging model and processing techniques. For the imaging model: the system design and parameters analysis will be presented, and the bistatic range history model and the motion error model will be established. For the imaging processing techniques: the 2-D space-variant frequency domain imaging algorithm, the fast bistatic time domain imaging algorithm and the motion compensation method will be studied to achieve well-focused GEO-UAV BSAR images for wide scene with high efficiency. We hope that the research results could be able to promote the development and practicality of GEO-UAV BSAR.

GEO-UAV BSAR是指以GEO SAR为发射源，以UAV搭载接收机的新型双基遥感系统。该系统具有机动灵活、响应迅捷、隐蔽性好的技术优势，能够对热点区域进行高时空分辨率的多角度观测与成像，在UAV采取曲线飞行轨迹的情况下还具有一定的三维成像潜力，应用前景广阔。然而，GEO-UAV BSAR在信息获取与处理方面也面临新的技术挑战。结合理论研究和工程应用，本项目拟针对GEO-UAV BSAR 成像模型与成像处理方法两个关键技术开展深入研究。成像建模方面：进行GEO-UAV BSAR系统设计与参数分析，建立双基距离历程模型和运动误差模型。成像处理方法方面：针对GEO-UAV BSAR成像特性，研究二维空变频域成像处理方法、快速双基时域成像处理方法以及运动误差补偿方法，进而实现高效、高精度的GEO-UAV BSAR成像处理。项目研究成果将为新体制BSAR系统的实用化奠定理论基础。

GEO-UAV BSAR是指以GEO SAR为发射源，以UAV搭载接收机的新型双基遥感系统。该系统具有机动灵活、响应迅捷、隐蔽性好的技术优势，能够对热点区域进行高时空分辨率的多角度观测与成像，在UAV采取曲线飞行轨迹的情况下还具有一定的三维成像潜力，应用前景广阔。然而，GEO-UAV BSAR在信息获取与处理方面也面临许多新的技术挑战。结合理论研究和工程应用，本项目针对GEO-UAV BSAR 成像模型与成像处理方法两个关键技术开展了深入研究。成像建模方面：分析了信噪比和分辨率等系统成像性能，提出了一种GEO-UAV BCSAR系统概念；分别针对UAV平台采取直线飞行轨迹和曲线飞行轨迹两种情况，建立双基距离历程模型和运动误差模型。成像处理方法方面：针对GEO-UAV BSAR双基距离历程不满足双曲线结构和目标回波响应具有方位-距离二维空变特性的问题，提出了一种基于直达波补偿的频域成像算法；针对BP算法运算量巨大的问题，基于二维插值设计实现了快速BP成像算法；分别针对航向运动误差和LOS向运动误差设计补偿方案，建立了完整的GEO-UAV BSAR运动补偿方法。依托高性能集群，设计实现了GEO-UAV BSAR全链路仿真系统；综合考虑GEO-UAV BSAR系统特性，设计了一种GEO-UAV BSAR快速回波模拟方法，兼具精度和效率。本项目研究成果将为新体制BSAR系统的实用化奠定理论基础，对我国双基地SAR成像技术研究有一定的推动作用。