A Crosscutting Three-Modes-Of-Operation Unique LiDAR-Based 3D Mapping System Generic Framework Architecture, Uncertainty Predictive Model And SfM Augmentation
thesisposted on 26.10.2021, 17:28 authored by Ashraf Mohamed Abdelaziz Elshorbagy
The need for 3D mapping is on the rise to meet the requirements of a growing and diverse group of end-users. Existing 3D mapping systems, which have been classified according to the mode of operation as stationary, mobile and aerial, tend to serve one mode of operation only and are considered cost-prohibitive for many end-users. Unmanned aerial vehicles (UAVs) have experienced rapid growth since their introduction and their usage in 3D mapping is likewise accelerating at a rapid pace. This dissertation presents the design, development and implementation of a LiDAR-based generic 3D mapping system that can be used in the three mapping modes (stationary, mobile and UAV-based). The system provides direct georeferencing capabilities through optimized selected multimodal sensors. A fundamental part of this dissertation is the smart integration of the 3D mapping system components both on the hardware and software levels, along with a new mapping scheme that enables platform-independent deployment ability.
This research project also presents a rigorous non-linear uncertainty predictive model for the generic developed system and introduces a very low-cost variant of the system to be used in stationary and handheld mode. The developed multipurpose mapping system is tested in different environments for the three modes of operation, demonstrating its practicality, versatility and ease of deployment. To maximize the ease of deployment for diverse end-users, careful consideration is given to the mapping system components so that the developed system is ultra-lightweight, compact, and multipurpose. Additionally, this dissertation proposes a colorization workflow to make use of available optical imagery in the colorization process of the LiDAR point cloud. Lastly, the study compares two different 3D mapping approaches: 3D LiDAR-based mapping and a low-cost optical-based 3D structure from motion (SfM) workflow. The comparison is achieved by performing a real-world case study of digital surface model (DSM) generation by the two aforementioned approaches. Real-world testing that includes qualitative and quantitative validation against accurate state-of-the-art high-end LiDAR equipment proves the successful design, development and deployment of the developed crosscutting LiDAR-based 3D mapping system.