Testing and evaluating different LiDAR-derived canopy height model generation methods for tree height estimation

The obtained results indicate that the method of generating CHMs influences the accuracy of tree height estimations. The mean differences between the means of field heights and LiDAR-derived heights (for each CHM separately and the 99th percentile) were statistically significant. The most accurate results were obtained with the spike-free CHM (RMSE calculated for all trees was 1.42 m (5.80%)). The smallest errors were observed for conifers-the RMSEs obtained for the spike-free CHM were 1.07 m (3.75%) and 1.18 m (4.57%) for spruce and pine, respectively. The use of linear regression improved the accuracy of tree height estimations from LiDAR data (especially for the CHMs filtered with Gaussian and median filters).