机载激光测深回波波形分解及折射率改正方法研究

Airborne laser bathymetry is one of the most advanced seabed topography surveying methods in present marine surveying and mapping and has a wide application prospect. But there are still many problems that have not been well solved. Such as waveform decomposition, seabed point cloud registration and sea water refractive index correction. So the precision and reliability of the laser bathymetry data processing are still under the exploratory stage. To solve the problems above, according to the geometric feature and prior knowledge of the airborne laser echo waveform, a marked point process based method is used to decomposition waveform of airborne laser bathymetry. And the accuracy and reliability of airborne laser bathymetry data can be improved. Secondly, based on the characteristics of seabed topography, this project studies reliable and effective data registration algorithm for seabed point cloud. Finally, an accurate seawater refractive index correction model is constructed based on the corresponding characteristic points of point cloud registration. And the error estimation model of laser bathymetry data caused by the change of refractive index is further deduced. The research work of this project can effectively improve the quality of airborne laser bathymetry data. It also can promote the development and application of airborne laser bathymetry system in China, and provide information support and reference for reasonable development planning of shallow sea area.

机载激光测深是当今海洋测绘领域最为先进的水深地形测量方法，具有广泛的应用前景。但机载激光测深存在着回波波形分解、海底点云数据配准、海水折射率改正等关键问题有待解决，导致激光测深数据处理精度和应用可靠性仍处于探索阶段。为此，本项目首先结合机载激光测深回波波形的几何特征以及先验知识，研究基于标记点过程的激光测深回波波形分解方法，提升机载激光测深数据的准确性与可靠性；其次基于海底地形特点，研究可靠有效的海底点云数据配准算法；最后根据点云配准中产生的同名特征点，构建精确的海水折射率改正模型，并进一步推导由折射率变化引起的激光测深数据误差估算模型。本项目的研究可以有效提高机载激光测深数据的质量，促进机载激光测深系统在我国的发展和应用，为浅海区域的合理发展规划提供信息支持和参考依据。

机载激光测深是当今海洋测绘领域的先进水深地形测量方法，具有广泛的应用前景。但机载激光测深数据处理中的精确回波信号分解、海底点云数据配准、海水折射率改正等关键问题仍有待解决，导致激光测深数据处理精度和应用可靠性仍处于探索阶段。为此，本项目首先结合机载激光测深全波形数据的形态特征以及先验知识，进行了机载激光测深回波信号分解参数优化方法比较，提出了基于波形分类的单频机载激光测深回波信号分解方法，可有效提高回波信号峰值探测的准确度与可靠性。其次基于机载激光测深系统获取点云特性以及海底地形特点，在对当前机载激光测深数据配准方法比较分析的基础上，分别研究了基于特征曲线以及基于权值分配的海底点云精确、稳健配准方法，并基于特征融合实现了海岛区域卫星影像与机载激光测深数据的配准。然后基于测深激光脉冲传播过程，提出了顾及海面波动的机载激光测深折射误差改正模型，将该模型扩展应用到星载激光测深数据的折射校正，可有效提高激光测深数据的精度。并研究了海水折射率改正，分析了由折射率变化引起的激光测深误差。最后选用了不同海底地形、不同深度环境下的机载激光测深数据对本项目提出的相关算法进行验证和评估。本项目的研究可有效提高机载激光测深数据的质量，促进机载激光测深系统在我国的发展和应用，为浅海区域的合理发展规划提供信息支持和参考依据。