星载激光测高系统大气折射延迟的影响分析

星载激光测高系统发出的测距光束经过大气层时会发生折射，由此产生的与大气延迟相关的测距误差在数米量级。讨论了激光测高系统大气延迟修正理论及实现算法，通过使用沿天顶方向的大气传输延迟值与非天顶方向相应映射函数乘积的方法来计算大气延迟，并对影响大气延迟主要气象参数地表气压进行修正。结合全球首个对地观测星载激光测高系统GLAS测量数据和美国国家环境预报中心NCEP气象数据进行大气延迟修正，并与GLAS系统公布延迟数据对比。结果表明:大气干项延迟偏差小于2 cm，湿项延迟偏差小于1 mm。

Analysis on atmospheric refraction delay for satellite laser altimeter system

The laser pulse transmitted from satellite laser altimeter system would be refracted by atmosphere and the range error in the system was about a few meters. In this paper the atmospheric refraction delay based on refraction models and mapping function was calculated, and the method of air pressure correction were discussed. Combined with the elevation data of geoscience laser altimeter system (GLAS) and meteorological parameters of national center for environment prediction (NCEP), the atmospheric delay was calculated and compared to the GLAS results. The comparison shows the deviation of hydrostatic and wet atmospheric delay are less than 2 cm and 1 mm respectively.