弹载合成孔径雷达弱特征区景象匹配制导实时图的高效高精度几何校正方法研究

Missile borne Synthetic Aperture Radar (SAR) is used for the scene matching to correct the error of the Inertial Navigation System (INS) has become an effective measure to improve the precision of the missile guidance system. Due to the side-looking and topographic changes on SAR imaging geometry, the geometric distortion of SAR real-time image will affect the precision of the scene matching, thus the geometric correction processing is needed. Compared with the air borne and space borne SAR systems, the geometric correction of the missile borne SAR real-time image needs to solve some special issues caused by the applications and platforms. Here we studied on "the interfering factors and characteristics analysis of the geometric correction precision for the missile-borne SAR image", "missile-borne SAR imaging with high dynamic motion parameter modeling", "the high efficiency and high precision geometric correction method in non zero Doppler imaging" and "the correction method for image geometric distortion in rugged scene" etc. Focused on "the high precision modeling for the high dynamic motion parameter of missile borne SAR imaging", "the system error self-correction technology of the missile borne SAR input parameters" and "the high accuracy approximation method for SAR geometric correction model in non zero Doppler imaging", proposed the high efficiency and high precision geometric correction method for missile borne SAR real-time image, therefore improved the guidance adaptability and guidance precision of the SAR scene matching.

利用弹载SAR进行景象匹配修正INS误差，已经成为提高导弹制导精度的一种有效措施。目前，由于弹上无法实现SAR图像的实时高精度几何校正，从而要求景象匹配区高程起伏较小且含有典型地物特征。而地形起伏较大、不含典型地物特征的弱特征区，由于其SAR图像几何畸变严重，不能作为目前弹载SAR的景象匹配区，这严重制约了导弹武器的实际作战能力。本课题围绕"弹载SAR图像几何校正精度影响因素及规律分析"、"高动态运动参数建模"、"非零多普勒成像条件下弱特征区实时图高精度几何校正方法"、"崎岖场景图像几何畸变校正方法"等内容开展深入研究，重点解决"弹载SAR成像高动态运动参数的高精度建模"、"弹载SAR输入参数的系统误差自修正技术"和"非零多普勒成像条件下SAR几何校正模型的高精度逼近方法"三项关键技术问题，提出高效高精度弹载SAR弱特征区实时图几何校正方法，从而提升弹载SAR景象匹配制导适应性和制导精度。

合成孔径雷达（SAR）可以全天时、全天候进行高分辨成像，利用弹载SAR进行景象匹配修正惯性导航系统（INS）误差，成为提高制导精度的一种有效措施。SAR景象匹配制导是利用弹载SAR获得包含典型地物的实时图，与预先存储在弹上的基准图进行匹配处理，从而获得成像时刻实时图的位置信息，然后根据导弹成像几何关系解算导弹空间位置，进而修正INS的位置误差。. SAR实时图存在几何畸变，影响景象匹配精度。为了获得较高的景象匹配精度，需要对SAR实时图的几何畸变进行校正。弹载SAR实时图几何校正技术面临的主要瓶颈问题是高精度与实时性的矛盾。本项目通过研究弹载SAR复杂地形区域实时图高效高精度几何校正方法，进而拓展SAR景象匹配区范围，提高SAR景象匹配制导适应性和制导精度，为提升导弹武器作战效能提供技术支撑。. 本项目研究内容包括五个技术问题：弹载SAR图像几何校正精度影响因素及规律分析、弹载SAR成像高动态运动参数的高精度建模、非零多普勒成像条件下弱特征区SAR实时图高效高精度几何校正方法、崎岖场景下弹载SAR图像的高精度几何校正方法、弹载SAR平台运动参数测量精度低情况下的高精度几何校正方法。.项目针对突破了弹载SAR弱特征区实时图几何校正处理中的一系列关键技术，将传统SAR几何校正方法的处理速度提升数十倍以上，精度损失在厘米量级，利用仿真和实测数据进行了试验验证，部分技术已成功应用于相关型号，为提高SAR景象匹配制导精度、可靠性和适应性提供了技术支撑，经济军事效益显著。.