一种新的校正电离层相位污染的相位梯度平均法

A Novel Method of Phase Gradient Average for Correcting Ionospheric Phase Contamination

为减轻电离层相位污染对天波超视距雷达(OTHR)目标检测性能的影响,降低已有污染校正方法带来多普勒谱移动以及实现复杂度,提出一种新的相位梯度平均法.该方法利用电离层扰动的慢变特点,通过在一个相干积累时间单元(CIT)中对相位梯度求平均来估计电离层相位失真.通过计算机仿真对新方法进行了分析,并与PGA方法和已有的改进PGA方法进行了比较.理论与仿真分析结果表明:提出的相位梯度平均法可较好的校正电离层污染,且处理后多普勒频移较小,实现简单,有利于改善天波超视距雷达对舰船目标的检测性能.

This paper proposes a novel method of phase gradient average to lessen the influences of ionospheric phase contamination on the target detection of over-the-horizon radars （OTHR） and lower the Doppler spectrum shift resulted from some existing methods of ionospheric contamination correction as well as its complexity of implementation. By taking advantage of slow-varying features of ionospheric disturbances and averaging the phase gradient in a unit of coherent integration time （CIT）, the ionospheric phase distortion is estimated in this method. Through simulation the characteristics of the new method is elaborated and the comparisons between the new one and PGA as well as improved PGA methods are also made. Theoretical analysis and its simulation results show that this method can correct the ionospheric contamination well with smaller Doppler spectrum shift and easy implementation, and it is helpful for improving ship target detection via the OTHR.