LiDAR flight parameter influence on low vegetation height inversion: A case study of DJI Zenmuse L1

The plant community height is an important factor that reflects vegetation growth. LiDAR technology is often used for forestry height inversion because of its penetration; however, its application in low vegetation height inversion remains limited. We used DJI L1 LiDAR to extract vegetation point cloud data under different flight altitudes, hovering times, and positioning systems at Gaolan Ecological and Agricultural Research Station. We compared the calculation and field measurement results to explore the influence of different factors. The results indicated that the Drtk and Nrtk positioning system accuracies were similar. The Drtk system could be used when there was no network. Although the inversion accuracy of a 10 s hover time was slightly higher, there was no significant difference in the accuracy between the 5 s and 10 s hovering times. When the vegetation height was < 60 cm, the flight height could be set to 20 m, and when the vegetation height was > 60 cm, the flight height could be set to 40 m to expand the sampling range. The results showed that when the vegetation height was < 30 cm, the inversion errors were within ± 30%. However, there was an apparent underestimation when the vegetation height was > 40 cm. The results of this study are helpful for the application of DJI L1 LiDAR to obtain the height of low vegetation in a large area.