Analysis of cotton height spatial variability based on UAV-LiDAR

Abstract: The spatial variance of geometric information of farmland crops is the basis of field management.  Therefore, it has significance for variable mechanical operations to accurately obtain the spatial difference of crop height information.  In the present study, UAV-LiDAR was used to collect data at the cotton planting base in Korla to estimate the spatial differences in cotton plant height.  The crop height was estimated using the average height of a certain number of highest points per m 2 point cloud.  First, the plant heights of different spatial locations in the field were collected manually and compared with the system measurement.  The results showed that the maximum relative error of sampling was 12.73%, the error value was3.48 cm, and the height map was visualized.  In order to explain the height change of plant height in the direction of crop rows and vertical crop rows, this paper used the coefficient of variation as a measure.  The results showed that the plant height variation coefficient in the crop row direction ranged from 0.54-1.04 and the average variation coefficient was 0.73; perpendicular to the crop row direction, the crop height variation coefficient range was 0.06-1.27 and the average variation coefficient was 0.58.  The spatial difference information was characterized by the coefficient of variation of the geometrical features of the crop height.  This work can provide information for cotton field variable operation machinery and provide reference for the extraction of field crop geometric information. Keywords: LiDAR, plant parameter, spatial variability, plant height DOI:  10.33440/j.ijpaa.20200303.79 Citation: Liu K, Dong X Y, Qiu B J.  Analysis of cotton height spatial variability based on UAV-LiDAR.  Int J Precis Agric Aviat, 2020; 3(3): 72–76.