【摘要】 星载激光测高仪能够有效获取地面点的三维坐标信息且具有较高的高程精度,但是在大气传输中激光不可避免会受到云的影响。首先,根据GLAS(Geoscience Laser Altimeter System)地学激光测高系统记录的大气传输过程中的回波能量数据拟合回波波形;其次,采用微分零交叉法和Fernald法分别实现了云检测和云光学厚度的反演;最后,利用广东省MODIS (MODerate-resolution Imaging Spectroradiometer)数据以及北京地区AERONET(Aerosol Robotic Network)地面观测站实测数据进行了验证分析。结果表明:文中方法在激光测高卫星云光学厚度反演上具有较高的可信度,在实际情况下云光学厚度反演误差小于0.1,且云光学厚度小于1时,相对误差远远小于0.01,相关结论对国产卫星激光测高数据质量控制具有参考价值。更多还原

【Abstract】 Satellite laser altimetry can quickly and efficiently obtain the 3 D coordinate data of ground points with high precision elevation, but the laser was inevitably affected by clouds in atmospheric transmission. Firstly, echo waveforms were fitted according to the echo energy data recorded in the atmospheric transmission process by the geoscience laser altimeter system(GLAS). Secondly, the differential zero-crossing method and Fernald method were used to realize cloud detection and cloud optical depth inversion respectively. Finally, moderate-resolution imaging spectroradiometer(MODIS) data and aerosol robotic network(AERONET) ground station data from Beijing region were employed to perform a validation analysis. The results show that the method presented in this paper has a high credibility in the optical depth inversion of the cloud by laser altimetry satellite. In the actual situation,the cloud optical depth inversion error is less than 0.1, and when the cloud optical depth is less than 1,the relative error is far less than 0.01. The relevant conclusions are of reference value for the quality control of the laser altimetry data of domestic satellites.更多还原