The launch of GEDI opens a new era of forest structure monitoring using full-waveform LiDAR from space. Simulation of GEDI waveform is of great importance for the algorithm design and forest structure metric estimation. DART is a universal 3D radiative transfer model for simulating remote sensing signals by modeling light propagation in 3D landscape, with DART-RC adopting forward ray tracing and DART-Lux adopting bidirectional path tracing to model multi-mode multi-platform LiDAR signals. GEDI simulator is a semi-empirical model for simulating GEDI waveform with point clouds. In view of their different solutions, this study aims to evaluate and inter-compare the accuracy of DART-RC, DART-Lux, and GEDI simulator for simulating GEDI waveforms in forests. Because there are possible geolocation errors and 3D modeling uncertainty in real forests, we propose to adopt virtual forests (turbid medium, RAMI scenes) for consistency evaluation and real forests for accuracy evaluation. Metrics including (coefficient of determination), RMSD (root mean square deviation), RMSE (root mean square error), and bias were calculated from the normalized waveform intensities from different simulation methods.

中文翻译：

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用于模拟森林 GEDI 波形的 DART 模型和 GEDI 模拟器的相互比较


GEDI的推出开启了利用太空全波形激光雷达进行森林结构监测的新时代。 GEDI波形的仿真对于算法设计和森林结构度量估计具有重要意义。 DART 是一种通用 3D 辐射传输模型，通过对 3D 景观中的光传播进行建模来模拟遥感信号，其中 DART-RC 采用前向光线追踪，DART-Lux 采用双向路径追踪来建模多模式多平台 LiDAR 信号。 GEDI模拟器是一个用点云模拟GEDI波形的半经验模型。鉴于其不同的解决方案，本研究旨在评估和相互比较 DART-RC、DART-Lux 和 GEDI 模拟器在模拟森林中 GEDI 波形时的准确性。由于真实森林可能存在地理定位误差和3D建模不确定性，因此我们建议采用虚拟森林（浑浊介质、RAMI场景）进行一致性评估，并采用真实森林进行准确性评估。包括（确定系数）、RMSD（均方根偏差）、RMSE（均方根误差）和偏差在内的指标是根据不同模拟方法的归一化波形强度计算得出的。