Acquisition of crop growth information by airborne laser scanner

用航空激光扫描仪（ALS）观测水稻、大田作物、饲料作物、牧草等各种作物，同时调查这些作物在地面上的生长情况。通过对ALS数据和调查结果的分析，估算了作物的高度和作物冠层结构。从7种作物的实测高度与基于ALS的平均高度值之间的关系可以看出，水稻等垂直生长的薄叶作物的实测高度与玉米等水平生长的叶片作物的实测高度不同。这是因为激光脉冲进入群落的深度取决于作物的草型。我们还能够通过检查飞机发射的激光脉冲的空间分布来估计作物冠层的三维结构。

Various crops such as paddy rice, field crops, forage crops, and pasture grass were observed with the aerial laser scanner (ALS), concurrently with the investigation of the growth of these crops on the ground. The ALS data obtained and the results of the investigation were analyzed to estimate the heights of the crops adn crop canopy structures. From the relationships between the measured heights and the ALS-based mean height values for seven types of crops, it was shown that the measured heights of crops with vertically growing thin leaves, such as paddy rice, were different from those of crops with horizontally growing leaves, such as corn. This is because of the fact that the entry depth of the laser pulse into the communities depends on the grass type of the crops. We were also able to estimate three-dimensional structure of the crop canopy by examining the spatial distribution of the laser pulses to be emitted from aircraft.