中距離可搬型スキャニングライダーを用いた高所からの水稲植物面積密度垂直分布の推定

抄録

A middle range portable scanning lidar was applied from a 10-m height place to estimate vertical plant area density (PAD) profiles of rice canopy at different growth stages. Voxel-based canopy profiling method was applied for the estimation. Resultant PAD estimates showed over estimation at middle to lower layers with the root mean square errors of 0.36, 0.45, 0.95, 1.81 m²m^-3 in each stage. Laser beam coverage index Ω was calculated and related to absolute errors of PAD to investigate causes of the errors. This showed that lack of the number of incident laser beams into the internal canopy was a major cause of the error. Although the lidar-derived PAD showed overestimation in middle to lower layers, the PAD estimates of upper layers agreed well with the actual values. The accurate PAD estimates of upper five layers could offer good correlation to dry weight of ears with R²=0.988.