多项式建模解电离层相位污染阶数选择新方法

Novel order-select method of polynomial modeling for ionosphere phase perturbation correction

电离层相位污染使天波超视距雷达杂波频谱展宽,影响舰船等低速目标检测。针对这一问题,近年来发展了基于分段多项式相位建模和高阶模糊函数的(HAF)解电离层污染算法,如何合理地选取模型阶数是该算法的核心。给出了两种改进的自适应多项式建模阶数选择方法。并利用仿真方法进行了验证,结果表明:基于高阶模糊函数变换性质的频域和时域阶数选择方法的计算量较现有算法有较大提高,且频域法可在较低信噪比下准确判断多项式阶数。

Ionosphere phase perturbation made the clutter spectrum of sky-wave over-the-horizon radar （OTHR） spread and influenced low-speed object detection such as ship. Recently,an algorithm based on piecewise polynomial phase modeling and high-order ambiguity function （HAF） is developed aiming at this problem. How to select the model order rationally is critical in the algorithm application. Two improved order-selecting methods of self-adaptive polynomial modeling are proposed and verified by simulation. The results indicat that the new method （frequency-domain and time-domain） based on the transform characteristic of high-order ambiguity function is improved greatly in accuracy and the amount of calculation is reduced. And the polynomial order can be judged exactly with low signal-to-noise ratio （SNR） when employing the frequency-domain method.