Topographic laser scanning is a remote sensing method to create detailed 3D point cloud representations of the Earth's surface. Since data acquisition is expensive, simulations can complement real data given certain premises are available: i) a model of 3D scene and scanner, ii) a model of the beam-scene interaction, simplified to a computationally feasible while physically realistic level, and iii) an application for which simulated data is fit for use. A number of laser scanning simulators for different purposes exist, which we enrich by presenting HELIOS++. HELIOS++ is an open-source simulation framework for terrestrial static, mobile, UAV-based and airborne laser scanning implemented in C++. The HELIOS++ concept provides a flexible solution for the trade-off between physical accuracy (realism) and computational complexity (runtime, memory footprint), as well as ease of use and of configuration. Unique features of HELIOS++ include the availability of Python bindings (pyhelios) for controlling simulations, and a range of model types for 3D scene representation. HELIOS++ further allows the simulation of beam divergence using a subsampling strategy, and is able to create full-waveform outputs as a basis for detailed analysis. As generation and analysis of waveforms can strongly impact runtimes, the user may set the level of detail for the subsampling, or optionally disable full-waveform output altogether. A detailed assessment of computational considerations and a comparison of HELIOS++ to its predecessor, HELIOS, reveal reduced runtimes by up to 83 %. At the same time, memory requirements are reduced by up to 94 %, allowing for much larger (i.e. more complex) 3D scenes to be loaded into memory and hence to be virtually acquired by laser scanning simulation.
翻译:地形激光扫描是一种遥感方法,用于为地球表面建立详细的 3D 点云表。由于数据获取费用昂贵,模拟可以补充真实数据,只要具备某些前提:i) 3D 场景和扫描的模型,ii) 梁光互动的模型,在物理现实水平下简化为计算可行的模型,以及(iii) 模拟数据适合使用的应用程序。存在一些用于不同目的的激光扫描模拟器,我们通过展示 HELIOS++来丰富这些模拟。HELIOS+++是一个用于地面静态、移动、UAV基和空中激光扫描的开放源模拟框架。HELIOS++的概念为物理准确性(现实性)和计算复杂性(运行时间、记忆足迹)之间的取自计算,以及模拟模拟数据,通过模拟,通过模拟,将3D 图像的存储、 移动性数据流流流流流流、 进一步进行模拟, 将精确的磁力流流流流流式分析, 将生成到亚形分析。