Design and Experimental Study on an Innovative UAV-LiDAR Topographic Mapping System for Precision Land Levelling

Abstract

Topographic maps provide detailed information on variations in ground elevation, which is essential for precision farmland levelling. This paper reports the development and experimental study on an innovative approach of generating topographic maps at farmland-level with the advantages of high efficiency and simplicity of implementation. The experiment uses a low-altitude Unmanned Aerial Vehicle (UAV) as a platform and integrates Light Detection and Ranging (LiDAR) distance measurements with Post-Processing Kinematic Global Positioning System (PPK-GNSS) coordinates. A topographic mapping experiment was conducted over two fields in Henan Province, China, and primitive errors of the topographic surveying data were evaluated. The Root Mean Square Error (RMSE) between elevation data of the UAV-LiDAR topographic mapping system and ground truth data was calculated as 4.1 cm and 3.6 cm for Field 1 and Field 2, respectively, which proved the feasibility and high accuracy of the topographic mapping system. Furthermore, the accuracies of topographic maps generated using different geo-spatial interpolation models were also evaluated. The results showed that a TIN (Triangulated Irregular Network) interpolation model expressed the best performances for both Field 1 with sparse topographic surveying points, and Field 2 with relatively dense topographic surveying points, when compared with other interpolation models. Moreover, we concluded that as the spatial resolution of topographic surveying points is intensified from 5 m × 0.5 m to 2.5 m × 0.5 m, the accuracy of the topographic map based on the TIN model improves drastically from 7.7 cm to 4.6 cm. Cut-fill analysis was also implemented based on the topographic maps of the TIN interpolation model. The result indicated that the UAV-LiDAR topographic mapping system could be successfully used to generate topographic maps with high accuracy, which could provide instructive information for precision farmland levelling.

An Improved TransMVSNet Algorithm for Three-Dimensional Reconstruction in the Unmanned Aerial Vehicle Remote Sensing Domain

“…The algorithms mentioned above provide outstanding contributions to the field of multi-view stereo (MVS). Moreover, the application of 3D reconstruction technology in the field of UAV remote sensing [24] has been expanding, providing richer information and data for topographic surveying [25], urban planning [26], environmental monitoring [27], and other fields. By carrying photographic equipment for aerial photography using unmanned aircraft and processing and analyzing aerial images with 3D reconstruction algorithms, high-precision and high-resolution 3D maps [28] and models can be constructed, providing data support for other geographic information systems [29] and geoscientific research [30].…”

A Collaborative Path Planning Method for Intelligent Agricultural Machinery Based on Unmanned Aerial Vehicles

“…When compared with the handheld GNSS (global navigation satellite system) module or tripod-based total station, UAVs can achieve higher efficiency and can be applied to large-area operations [36]. So, we use UAVs to detect obstacles and mark the grids where the obstacles are located.…”

Stockpile Volume Estimation in Open and Confined Environments: A Review

“…Both RTK and PPK methods can achieve high accuracy, but they are used in different scenarios, based on the specific requirements of the survey, such as the need for real-time results, the available infrastructure, and other factors [31]. To transform GNSS data into a reconstructed 3D model, methods such as the Triangulated Irregular Network (TIN) and Inverse Distance Weighting (IDW) are among the most commonly used approaches [32]. Note that GNSS surveying only collects single points around and over the area of interest, and the accuracy of the modeled surfaces increases when more points are collected.…”