一维的FDTD程序，在自由空间的中心产生一个高斯脉冲，然后脉冲向两边扩散。-one-dimensional FDTD program,it generates a Gaussian pulse in the center of the problem space.

模拟高斯脉冲的发射和大气衰减，并给出了相干探测时波形的时频图像，适合新手。-This scr ipt simulates the emission of Gauss beam and the atmospheric attenuation. Besides,the wave shapes in time domain and frequency domain are shown,which is suitable for beginners.