Evaluation of Uncrewed Aircraft Systems’ Lidar Data Quality

Abstract

Uncrewed aircraft systems (UASs) with integrated light detection and ranging (lidar) technology are becoming an increasingly popular and efficient remote sensing method for mapping. Due to its quick deployment and comparatively inexpensive cost, uncrewed laser scanning (ULS) can be a desirable solution to conduct topographic surveys for areas sized on the order of square kilometers compared to the more prevalent and mature method of airborne laser scanning (ALS) used to map larger areas. This paper rigorously assesses the accuracy and quality of a ULS system with comparisons to terrestrial laser scanning (TLS) data, total station (TS) measurements, and Global Navigation Satellite System (GNSS) check points. Both the TLS and TS technologies are ideal for this assessment due to their high accuracy and precision. Data for this analysis were collected over a period of two days to map a landslide complex in Mulino, Oregon. Results show that the digital elevation model (DEM) produced from the ULS had overall vertical accuracies of approximately 6 and 13 cm at 95% confidence when compared to the TS cross-sections for the road surface only and road and vegetated surfaces, respectively. When compared to the TLS data, overall biases of −2.4, 1.1, and −2.7 cm were observed in X, Y, and Z with a 3D RMS difference of 8.8 cm. Additional qualitative and quantitative assessments discussed in this paper show that ULS can provide highly accurate topographic data, which can be used for a wide variety of applications. However, further research could improve the overall accuracy and efficiency of the cloud-to-cloud swath adjustment and calibration processes for georeferencing the ULS point cloud.

Natural Hazards Reconnaissance With the NHERI RAPID Facility

“…Herein, a simple accuracy assessment is provided. A rigorous accuracy assessment of the RAPID's UAS lidar can be found in Babbel et al (2019), which shows similar accuracy results to those presented in this case study. Ultimately, the ability to efficiently obtain data across the entire landslide, minimal time of mobilization, and overall quality of data made the UAS lidar the optimal choice for obtaining the post-event DEMs over alternatives such as terrestrial and airborne lidar and SfM/MVS photogrammetric methods.…”

River Morphology Monitoring of a Small-Scale Alpine Riverbed Using Drone Photogrammetry and Lidar

“…Many of these unmanned laser scanning (ULS) systems are still unreliable and at an experimental stage, operating lower-grade LiDAR sensors commonly used in robotics applications. However, recent studies based on UAVs equipped with dedicated mapping sensors demonstrated reliable collection of topographic datasets (Babbel et al, 2019;Mayr et al, 2019). ULS can produce accurate and very high spatial resolution point clouds, enabling more detailed characterisation of bare earth and microtopographic features.…”

Perceived Usefulness of Airborne LiDAR Technology in Road Design and Management: A Review

“…There are also a great deal of missing spot height data, particularly in areas which workers with TS have failed to enter or observe [19,20]. Furthermore, if inexperienced surveyors undertake the surveys, the acquired data are vulnerable to human error [21], such as the instruments being in poor condition, obstacles from steep slopes [22] and a lack of entrance access to the field measurement site [20]. Topographic features are primarily non-automated and require many individuals to check and observe the data collection process [23].…”