基于二阶散射的海面三尺度雷达后向散射模型

基于二阶组合表面模型和随机多尺度散射模型,本文提出一种既包含大尺度、中小尺度散射又包含二阶布拉格散射的海面雷达后向散射模型.在本模型框架下,我们推导了二阶布拉格散射的表达式,并根据弱流体动力作用理论推导出流体动力调制函数解析表达式.另外,我们通过全局和本地坐标系中观测角度的转换实现了倾斜调制.仿真结果表明该模型结果与实测数据相符,并优于前两者的模型结果.

基于实测数据的机载海洋波谱仪反演算法研究

波谱仪是用于测量海浪方向谱的实孔径雷达,因其具有测量精度高、测量波长范围大、可全天时全天候工作等特点,成为目前波浪谱测量的一个重要技术手段。基于海洋波谱仪机载挂飞试验录取的实测数据,对数据回波功率随入射角的变化特性进行分析,提出回波功率与斜距的二阶拟合模型,改进传统波谱仪反演算法中倾斜调制函数的估计方法,提高了波浪谱反演精度。

X波段导航雷达海浪数值模拟

针对X波段导航雷达海浪特性研究的需要,对海浪进行了数值模拟。采用经典PM谱作为靶谱,利用Longuest—Higgins模型仿真海浪,然后对仿真的海浪进行阴影调制和倾斜调制得到调制后的雷达图像,并经过海浪谱反演技术验证了仿真的可行性和准确性。

Continuous rotation north-finding algorithm based on constrained adaptive Kalman filter

As an orientation measurement system,north-finder has been playing a significant role in both military and civilian fields of orientation and control.In this paper,to deal with drawbacks in the conventional north-finding systems,a dynamic strategy based on continuous rotation modulation to measure the rotational angular velocity of the earth is proposed.By modeling the dynamic error,optimizing the process constraint and estimating dynamic noise,a method combining delay compensation and hardware adjustment,and a constrained adaptive Kalman filter(CAKF)algorithm are designed for the north-finding strategy.According to simulation and experiments,the proposed algorithm can achieve the high-precision north-finding with robust and anti-noise performance.