Study on the Refractive-Index Structure Coefficient C_N²

Based on the regularities of temperature fluctuation,the atmo- sphere below an altitude of 71km above ground is divided into 6 sublayers. For each of them the calculation formulae of temperature and pressure are derived.The calculated results at any altitude in the range under considera- tion agree well with the values laid down in the table of“U.S.Standard At- mosphere”.From this the formula for the refractive-index structure coeffi- cient C_N²,of much importance in the research of adaptive optics,is obtained for the corresponding altitudes.