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利用全波解算法模拟哨声波束在甚低纬地区黎明前低电离层透射的三维能量分布，依据波场能量和偏振分布及其对波参量和电子浓度剖面的依赖特征，分析了哨声透射、反射及与大地－电离层波导耦合过程．结果表明，哨声模波存在于９０ｋｍ以上高度，吸收、反射、波束扩展及波模转换主要发生于电离层底部８０－９０ｋｍ区间；到达地面的透射能量密度衰减２０ｄＢ以上，透射衰减随频率变化不大，但随波入射角呈不对称变化；距透射区１５０ｋｍ以外区域的测向方位角有很大偏差；入射波能量的很少一部分（对５ｋＨｚ约为－２５ｄＢ）被反射并激发起哨声模波，反射波束能量集中于入射波束附近，并随频率下降而迅速增强．计算也表明，地面接收到的甚低纬哨声回波可能与使回波向极侧偏移的电离纬向梯度有关．
Based on the wavefield energy and polarization distribution and its dependence on wave parameters and electron concentration profiles, the full wave solution algorithm was used to simulate the three-dimensional energy distribution of the whistle beam transmitted in low ionosphere before dawn in very low latitudes. , Reflection and coupling with the earth-ionosphere waveguide. The results show that the whistler mode wave exists at a height above 90km. The absorption, reflection, beam expansion and mode conversion mainly occur in the interval of 80-90km at the bottom of the ionosphere. The transmission energy density reaching the ground attenuates more than 20dB, and the transmission attenuation decreases with frequency Large but fluctuating asymmetrically with the incident angle; there is a large deviation of DF azimuths in the area 150 km away from the transmissive zone; a small fraction of the incident energy (~ -25 dB for 5 kHz) is reflected and the whistle is induced The mode and reflected beam energy is concentrated near the incident beam and rapidly increases with decreasing frequency. The calculations also show that very low latitude whistling echoes received by the ground may be related to the ionized latitudinal gradient that shifts the echoes to the polar side.