A vehicle-based laser system for high-resolution DEM development – performance in micro-topography measurement

Authors: LI, PENG - Kansas State University; ZHANG, NAIQIAN - Kansas State University; Wagner, Larry; Fox, Jr, Fred; OARD, DARRELL - Kansas State University

Submitted to: Biosystems Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/6/2022
Publication Date: N/A
Citation: N/A

Interpretive Summary: A vehicle-based laser measurement system was developed to measure surface roughness and to generate a high-resolution digital elevation model (DEM). The accuracy of the system in measuring surface roughness was evaluated in the laboratory by comparing the DEM data generated by the system with that generated by a more accurate, laser-based profile meter for an unknown surface. DEM data was created by interpolating the 3D raw data into a regular, square grid using a two-dimensional, distance-weighted interpolation algorithm. Comparison of the DEMs was done using an image matching method to calculate the correlation coefficient. A test to study the effect of various ambient light conditions had on surface roughness measurement under both indoor and outdoor environments was also conducted. The correlation coefficient of greater than 0.935 was achieved between the measured and reference DEMs. Results also showed that the laser system can provide consistent elevation measurements under both indoor and outdoor lighting conditions.

Technical Abstract: A vehicle-based laser measurement system was developed to measure the surface micro topography and to generate high-resolution digital elevation models (DEM). The accuracy of the system in micro topography measurement was evaluated in the laboratory by comparing the DEM data generated by this system with that generated by a more accurate, stationary laser profile meter for several surfaces, including an artificial sand-stone-ridged surface. DEM data was created by interpolating the 3D raw data into a regular, square grid using a two-dimensional, distance-weighted interpolation algorithm. Comparison of the DEMs was done using an image matching method to calculate the correlation coefficient. A test to study the effect of ambient light on elevation measurement under both indoor and outdoor environments was also conducted. Correlation coefficients greater than 0.935 were achieved between the DEMs measured by the vehicle-based system and the stationary laser profile meter. The correlation coefficients among the four replications of the DEMs measured by the vehicle-based system were greater than 0.988, indicating that the vehicle-based laser system can provide consistent elevation measurements. Correlation coefficients among the DEMs of the sand-stone-ridged surface measured by the vehicle-based system at different times of the day and under different indoor fluorescent lighting conditions were all above 0.982. Correlation coefficients among DEMs taken at different times of a day and under different outdoor sunlight conditions were all above 0.971. These results indicated that neither the fluorescent light nor the sunlight had a significant effect on the measurements obtained by the vehicle-based laser system. The system provided consistent elevation measurements under both indoor and outdoor lighting conditions.