Development of a model for strict handling of refraction in airborne lidar bathymetry

机载激光雷达测深是一种测量低浊度水体中浅水区水下地形的技术。最近，由于新的传感器的发展允许在扫描河床时实现更高的空间分辨率，以及由于欧盟新的法规要求定期在水体中进行水文测量，它得到了广泛的关注。机载激光雷达测深中的几何建模比传统的激光扫描更加复杂，因为需要对通过气-水界面的激光脉冲的折射效应进行建模，并且由于脉冲在水下的色散增加。目前的高分辨率激光雷达测深系统需要新的几何建模概念，因为在建立折射模型时，不能再忽略波浪对水面的影响。该方案的目的是在时空参数化水面模型的基础上，建立一个严格的几何随机模型，用于在激光雷达测深数据处理中考虑波浪影响，该模型允许对折射激光脉冲路径进行差分建模。因此，该模型将提供改进的折射效应校正，从而在机载激光雷达测深中获得更好的精度。

Airborne lidar bathymetry is a technique for the determination of the underwater topography of shallow water areas in waterbodies with low turbidity. It is recently gaining much attention both due to new sensor developments allowing for a much higher spatial resolution in scanning riverbeds and due to new EU regulations requiring hydrographic measurements in waterbodies at regular time intervals.Geometric modeling in airborne lidar bathymetry is more complex than in conventional laser scanning due to the necessity of modeling refraction effects of the laser pulse passing the air-water interface and due to an increased dispersion of the pulse under water. Recent high resolution lidar bathymetry systems require new concepts of geometric modeling, as the effects of waves on the water surface cannot be neglected anymore when modeling refraction. The goal of the proposal is to develop a strict geometric-stochastic model for considering wave effects in lidar bathymetry data processing on the basis of spatio-temporal parameterized water surface models, which allow for a differential modeling of the refracted laser pulse path. As a result, the model will deliver an improved correction of refraction effects and thus a better accuracy in airborne lidar bathymetry.