星载激光测高仪大气传输延迟对测距精度的影响  

Influence of atmospheric transmission delay of satellite laser altimeter on ranging precision

作　　者：赵欣[1] 张毅[1] 赵平建[1] 涂碧海[1] 

机构地区：[1]中国科学院合肥物质科学研究院安徽光学精密机械研究所,安徽合肥230031

出　　处：《红外与激光工程》2011年第3期438-442,共5页Infrared and Laser Engineering

基　　金：中国科学院合肥物质研究院院长基金资助项目

摘　　要：地球表层的大气折射可对激光测高仪的激光脉冲传输造成延迟,该延迟对激光飞行时间的测量精度以及地球表面三维轮廓的监测造成显著影响。因此,激光测高仪测距精度需要通过大气传播误差函数进行修正。着重讨论了激光脉冲基于天顶延迟的计算方法和相关映射函数模型的选择,并采用NMF连分式映射函数分别对干项和湿项进行计算。结果表明,在1.064μm波长,指向角偏差不超过10°的激光测高仪系统中,干项延迟可达2.35 m,为主要误差源,湿项延迟变化从1~4 mm不等,基本可以忽略。Atmospheric delay of laser pulse is the dominant error source for high precision range measurements of laser altimeter arisen from atmospheric refraction,the error source will greatly influence the measurement precision for pulse laser flight time,and faulty estimation in the three-dimension prediction.So the atmospheric model is needed to correct the propagation delay of the laser transmission in air.How to calculate the ray paths delay in atmosphere near zenith was presented,and some models of relative map function were given out.Through calculating and comparing these functions,the NMF function in a continued fraction was used to calculate separately for hydrostatic and wet components of the air.Result shows that laser altimeter transmitting with 1.064 μm laser and point angle under 10° off nadir,the zenith hydrostatic delay is approximately 2.35 m and is the major component of total delay;the corresponding zenith wet delay varing from 1 mm to 4 mm can be ignored.

关 键 词：激光测高 大气延迟 映射函数 天顶延迟 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]