大气折射修正的影响因素分析

大气折射率的非均匀分布导致了激光在实际大气传输时其传输路径偏离直线而发生折射,其传输轨迹为一条曲线。大气色散效应导致采用不同的波长分别瞄准和打击目标时其瞄准路径和激光传输路径不一样,地球因不同纬度处的半径和重力加速度g不同从而影响到大气折射修正,近年来日益增加的大气CO2浓度也成为影响大气折射修正精度的一个因素,在大气球面分层模型下研究了可见光到近红外波长段、不同纬度和CO2浓度对大气折射仰角误差的影响。仿真结果表明,从可见光到近红外波段的波长段和整个纬度对折射误差的影响在0.1″量级,CO2浓度的影响量级在0.001″量级。在修正精度要求较高的场合,波长和地球纬度对大气折射修正的影响不可忽略。

Analysis of Factors on Atmospheric Refractive Modifying

Because of the inhomogeneous distribution of the atmosphere refractive index,laser locus will off the direct path and refract to a curve.Atmospheric dispersive effect causes the difference of aiming and transport path when adopting different wavelenghs to aim and strike an object,latitude on earth effects the atmospheric refractive error by effecting the earth radius and g.The increasingly CO2 thickness also becomes a factor of atmospheric refraction modification accurency.The effects of wavelength,latitude,atmospheric thickness on atmospheric refractive elevation angle error were discussed under atmospheric layered model.The simulated data shows that the wavelength from visible to close infrared and the whole latitudes both influence the elevation angle error in 0.1″,CO2 thickness’ influence is at 0.001″.For the high precision applications,the effects of wavelength and latitude to refractive modification can’t be neglected.