一种火星大气密度三维解析模型

根据火星大气数据库,建立了以高度和经纬度为输入的火星三维解析大气密度模型;在竖直方向上,采用分层指数模型;在水平方向上,将指数模型中的参考密度和参考高度视为经纬度的多项式函数,并通过最小二乘曲面拟合得到了多项式系数。相比传统的指数模型,三维指数模型不仅反映了火星大气密度随高度的变化规律,而且能够体现出大气密度在水平方向上的变化。与大气数据库相比,三维密度模型具有解析形式,计算速度快,仿真过程中只需存储简单的多项式系数即可实现密度的实时计算和调用,适用于地面实时仿真。

Three-Dimensional Analytical Model for Mars Atmospheric Density

This paper utilizes the data from the Mars atmosphere database and establishes a three-dimensional analytical atmospheric density model of Mars with the altitude,longitude and latitude as its input..The layered exponential model is adopted vertically.At horizontal direction,the reference density and reference altitude are assumed to be polynomial functions of longitude and latitude.The coefficients of the polynomial are obtained by surface fitting which is based on the method of least squares.Compared with the traditional exponential density model,the3-D model proposed in this paper expresses the variation of density with not only altitude but also long itude and latitude.Compared with the Mars atmosphere data,the 3-D model has an analytical formulation and requires less calculation time.As long as the polynomial coefficients are stored in simulation,the real-time calculation and calling of the atmospheric density can be achieved,which applies to the ground real-time simulation.