A Vehicle-Based Laser System for High-Resolution DEM Development – Performance Evaluation of System Components.

Surface microtopography is quantified by the deviations in the direction of the normal vector of the surface. Soil microtopography is a major factor influencing soil erosion by water and wind. Surface microtopography can be accurately described using the Digital Elevation Model (DEM). In this study, a vehicle-based laser system was developed to generate high-resolution DEM data. The system consisted of five major components: a laser line scanner, a gyroscope sensor, a real-time kinematic GPS, a frame-rail mechanism, and a data acquisition and control unit. A series of experiments were conducted in the laboratory to evaluate the performance of the components. The result of distance measurements indicated that the system gave the most consistent distance measurement on a white paper. Static gyroscope sensor accuracy tests showed that angle measurement errors observed in combined pitch/roll rotations were larger than in single rotations. Within ±30º of single rotations, the measurement errors for pitch and roll angles were within 0.8º and 0.4º, respectively. The tests of the angular displacement on the linear rail showed that it slightly tilted towards the laser line scanner when it moved along the rail.