星-地下行传输孔径接收闪烁频谱的理论和实验研究

基于孔径接收的对数振幅相关函数,结合星地激光下行链路的实际情况,推导了星地下行孔径接收的闪烁频谱表达式。分析了天线孔径和天顶角对闪烁频谱的影响。通过恒星观测实验,对下行孔径接收的闪烁频谱进行了实际测量。实验结果验证了理论计算。研究表明,下行孔径接收的闪烁频谱分为低频段和高频段两部分。低频谱为常量,高频谱呈指数关系变化,指数下降因子为(-11/3)。随着接收孔径尺度增加或天顶角减小,频谱幅值逐渐减小,但闪烁频谱的形状保持不变。

Theoretical and Experimental Study on Power Spectrum of Atmospheric Scintillation with Large-Aperture Receiver for Satellite-to-Ground Downlink Pan Fang

Based on the temporal covariance of logarithmic amplitude and the practical conditions,the analytical expression is obtained for aperture receiving power spectrum of atmospheric scintillation of satellite-to-ground downlink.The effect of the receiving aperture and zenith angle on the power spectrum of atmospheric scintillation is analyzed.The experiment of detecting stellar intensity is accomplished with a large antenna.The real power spectrum of atmospheric scintillation is obtained.The results of experiment accord well with these of theoretical analysis.The results show that the power spectrum of atmospheric scintillation includes low-frequency and high-frequency spectrum.The amplitude of low-frequency spectrum is constant.The high-frequency spectrum obeys the power law and the value of power-law is-11/3.The amplitude of power spectrum gradually reduces with the aperture scale adding or the zenith decreasing,and the shape of power spectrum is unvariable.