The use of airborne lidar for orchard tree inventory

Abstract

The tree inventory in orchards is of great interest for orchard management and for government insurance plans. However, the conventional inventory is time‐consuming and expensive. Here a remote sensing method is introduced for orchard inventory. Airborne LIDAR (light detection and ranging) data were employed to obtain tree topography, and multispectral images were used as a reference. LIDAR vector data were converted to raster data for tree crown delineating purpose and in order to be easily superimposed on multispectral data in the same database. A tree crown delineation model was developed using a tree height image derived from the difference between canopy and ground LIDAR altitudes. The number of trees was computed from the delineation model. Spatially separated trees were precisely counted by fine definition of their crowns. For larger trees, although they have irregular crown form, like multi‐tops, holes in the centre or overlapped branches, the model developed in this study provided reliable results for crown delineation.