Kenshin YAGINUMA Study on The Influence of Observation Conditions on Paddy Rice Growth Monitoring by Drone LiDAR Measurement Kazuyoshi Takahashi In this study, there was a difference in the results of the community group when the observation conditions were different in the drone LiDAR measurement in previous studies, so by clarifying the relationship between the observation conditions and the vertical distribution of the group of drop points, Therefore, the purpose of this study was to focus on the shape of the laser footprint and the size of the laser footprint diameter, and to examine the relationship between the vertical distribution of the cluster points. The effect of the shape of the laser footprint was to obtain rice measurement points on a course parallel to the same paddy field and a course perpendicular to the same paddy field using a drone LiDAR system with a rectangular laser footprint shape. The results suggest that there was no difference in the vertical distribution of the drop points between the courses except for one period when the wind speed was large at the time of measurement, and that the vertical distribution of the drop points could be obtained without being affected by the shape of the laser footprint if the laser footprint diameter was of the same size. The effect of the size of the laser footprint diameter is based on a prototype simulation model that estimates the vertical distribution of the colony given by the stalk leaves under the condition that the laser is directly incident into the colony, and in 2022 the measurement altitude was 10 m and the scanning angle was -90The results of this simulation model were adjusted according to the size of the laser footprint diameter by adjusting the FSI when estimating the vertical distribution of the community point group. In the early stages of growth, there is no significant change in the vertical distribution of the cluster when the FSI is adjusted, so it is difficult to determine the FSI unless the paddy rice grows to a certain extent.