基于空时协方差矩阵拟合的湍流谱宽估计方法  

Turbulence spectral width estimation method based on space-time covariance matrix fitting

作　　者：李海[1] 湛蕾 吴仁彪[1] 

机构地区：[1]中国民航大学天津市智能信号与图像处理重点实验室,天津300300

出　　处：《中国民航大学学报》2018年第1期20-24,共5页Journal of Civil Aviation University of China

基　　金：国家自然科学基金项目(61471365)

摘　　要：大气湍流是飞机在高空飞行时会碰到的一种气象目标。针对低信噪比下大气湍流的检测估计,提出一种基于空时协方差矩阵拟合的机载气象雷达湍流回波谱宽估计方法。首先利用湍流回波频谱呈现高斯谱的特性建立湍流目标空时协方差矩阵的参数化模型,然后将估计的湍流回波信号协方差矩阵与参数化模型进行拟合,构造代价函数,最后通过对代价函数的搜索来实现对湍流回波谱宽的精确估计。仿真结果表明,该方法在回波信噪比较低的情况下能够准确估计湍流谱宽。Atmospheric turbulence is a kind of weather target that aircrafts will encounter at high altitude flight. Aiming at the detection of atmospheric turbulence under low SNR （signal-to-noise ratio）, a method for estimating the turbulence echo spectral width of airborne meteorological radar is proposed based on space-time covariance matrix fitting. Parametric model of the turbulence target space-time covariance matrix is established by using the Gaussian spectrum characteristics of turbulence echo spectrum. Then, the estimated covariance matrix of turbulence echo signal is fitted with the parametric model to construct cost function. Finally, the exact estimation of turbulence wave width is realized by searching the cost function. Simulation results show that the proposed method can accurately estimate the turbulence spectrum in low SNR condition.

关 键 词：机载气象雷达 大气湍流 协方差矩阵 谱宽估计 

分 类 号：V243[航空宇航科学与技术—飞行器设计] TN974[电子电信—信号与信息处理]