电离层闪烁功率谱及不均匀体漂移速度反演

Power spectrum of ionospheric scintillation and inversion of drift velocity of irregularities

从Rytov理论出发,给出了弱起伏下一般平静电离层电波传播的闪烁指数。研究表明:尺度为第一菲涅耳带的电子密度不均匀体对电离层电波闪烁的贡献应起主要作用。进而在Shkarofsky不均匀体幂率谱基础上,给出了闪烁的功率谱,并对影响闪烁功率谱的主要因素作了具体分析。同时,在给定不均匀体离地高度的情况下,通过对闪烁功率谱函数振荡部分出现第一极小值时的频率和总功率谱曲线出现第一极小值时频率的比对,反演得到了不均匀体的漂移速度。最后实验分析表明:在误差范围内,该结果能正确反映电离层不均匀体的真实漂移速度。

Based on the Rytov approximation theory, the scintillation index of the radio wave is discussed, which propagates through the random medium of the generic calm ionosphere under weak fluctuation. The results show that the irregularity sizes of the first order Fresnel zone are most important in causing the amplitude scintillation. By using the Shkarofsky spectrum, the power spectrum of the scintillation is presented, and analysis for the main factors on the intensity spectrum are given. Meanwhile, when the distance between the ground and the irregularities is given, by comparing the frequency which corresponding to the minimum value of the oscillation function and the frequency corresponding to the minimum value of the total power spectrum, the drift velocity of the irregularities is obtained. Within the limitation of the errors, this result can accurately reflect the true drift velocity of the ionosphere irregularities.