说明：  低轨卫星LEO通信系统的多普勒频移估计，通过该程序可以画出多普勒频移的S曲线，可以观测处最大的多普勒频移以及变化率
(LEO LEO satellite communication system of the Doppler frequency shift is estimated that the program can be drawn through the Doppler shift of the S curve can be observed to be the highest Doppler frequency shift and the rate of change)