| The recent advances in Light Detection and Ranging (LiDAR) have allowed for the remote sensing of important forest characteristics to be more reliable and commercially available. The purpose of this study was to provide some insight into the current capability of some commercially available software programs in obtaining bio-physical properties of forests through LiDAR remote sensing. The study assessed the accuracy of LiDAR-derived estimates of forest characteristics including tree crown radius, height, and timber volume against conventional methods of estimation using field-measured samples. The software programs compared in this study are TiFFS (Toolbox for LiDAR Data Filtering and Forest Studies), TreeVaW (Tree Variable Window), and LiDAR Analyst 4.2. Three methods of LiDAR Analyst were compared due to the number of parameter associated with the program.;TreeVaW, though not developed as a commercial program, performed the overall best with root mean square error (RMSE) being 12.97 (64.5% of the field mean) for tree count per plot, 5.43 meter (26.5%) for tree height, 1.31 meter (40.7%) for crown radius, 2.71 inch (20.9%) for DBH, and 104.92 cubic foot per acre (65.2%) for timber volume. However, TreeVaW requires the input dataset being a canopy height model in ENVI raster format that has to be processed from raw LiDAR data using other programs beforehand. TiFFS performed with the least accuracy due to its overestimation on tree count. That resulted in a RMSE of 32.36 (161%) for tree count per plot, 5.45 meter (26.5%) for tree height, 1.87 meter (58.2%) for crown radius, 2.74 inch (21.1%) for DBH, and 372.04 cubic foot per acre (231.2%) for timber volume. Even though TiFFS achieved an unsatisfactory accuracy, it had higher correlations between the field-measured and LiDAR-derived data than other programs, with the correlation coefficient (r) at 0.8228 and 0.7076 for mean tree height and timber volume per plot, respectively. If allowing for calibration with training data, TiFFS would be a valuable LiDAR data processing program with its low cost and ease of use.;LiDAR Analyst was able to estimate not only crown radius but also DBH. However, its performance is unreliable due to its inability to generate an accurate bare-earth surface in a highly forested area. In turn, this program detected much fewer trees than what were in the field. Even though it allows for user defined parameter input, the outcomes are inconsistent. |
