Applying airborne LiDAR for forested road geomatics

Abstract
Airborne Light Detection and Ranging (LiDAR) has become a popular remote sensing technology to create digital terrain models and provide forest inventory information. However, little research has been done to investigate the accuracy of using scanning airborne LiDAR to perform road geomatics tasks common to forest engineering. We used airborne LiDAR to estimate existing forest road characteristics in support of a road assessment under four different canopy conditions. In estimating existing road centerlines, LiDAR data had a vertical root mean squared error (RMSE) of 0.28 m and a horizontal RMSE of 1.21 m. Road grades were estimated to within 1% slope of the value sampled in the field and horizontal curve radii were estimated with an average absolute error of 3.17 m. The results suggest that airborne LiDAR is an acceptable data source to estimate forest road centerlines and grades, but some caution should be used in estimating horizontal curve radii, particularly on sharp curves.