Cloud scattering influence on satellite laser altimetry data and its correction

Satellite laser altimetry can obtain submeter or even centimeter-level surface elevation information over a large range. However, the laser will inevitably be affected by clouds during transmission through the atmosphere, which seriously affects the accuracy of altimetry. In this paper, based on laser altimetry data, cloud optical depth inversion was realized by using the Fernald method. The influence of clouds on the echo waveform data was analyzed with actual data, and a method of cloud scattering error correction was proposed. The existing error correction methods are mostly based on the results of semi-analytical Monte Carlo simulations. In observations, it is difficult to synchronously obtain the parameters required for simulation, which significantly limits the method. Therefore, a method for correcting the cloud scattering error of satellite laser altimetry data based on an exponential model is also proposed. The experimental results show that when the cloud optical depth is 0-2, the root mean square error of the model is 0.05, which can correct the height measurement deviation caused by the cloud to within 5 cm and improve the availability of the laser height measurement data affected by the cloud scattering.