中文说明：
本Matlab程序对需要高速穿越大气层的返回舱进行了纵向三自由度的模拟计算，只需输入如下基本参数，初始速度，再入高度，再入角。程序中有比较详细的说明。大气模型采用了真实的1976年美国标准大气模型，内附计算标准大气模型的Matlab程序，只需输入高度和高度间隔即可求出详细的参数值。
English Description：
This matlab program is used to simulate the longitudinal three degrees of freedom of the reentry module which needs to pass through the atmosphere at high speed. It only needs to input the following basic parameters, initial velocity, reentry height and reentry angle. There are more detailed instructions in the program. The real American standard atmospheric model of 1976 is used in the atmospheric model. The matlab program for calculating the standard atmospheric model is attached. The detailed parameters can be obtained by inputting the altitude and altitude interval