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Integration of LiDAR and Photogrammetric Data
Published in Jie Shan, Charles K. Toth, Topographic Laser Ranging and Scanning, 2018
Orthophoto production focuses on the elimination of the sensor tilt and terrain relief effects from captured perspective imagery. Uniform scale and the absence of relief displacement make orthophotos an important component of geographic information systems databases, in which the user can directly determine geographic locations, measure distances, compute areas, and derive other useful information about the area in question. Recently, with the increasing availability of overlapping LiDAR and photogrammetric data, which is acquired from aerial and satellite imaging platforms, there has been a persistent need for an orthophoto generation methodology that is capable of dealing with imagery acquired from such systems. Moreover, the increasing resolution of available data mandates the development of true orthophotos, in which occluded portions of the LiDAR surface are reliably detected in the involved imagery.
Integration of LiDAR and Photogrammetric Data: Triangulation and Orthorectification
Published in Jie Shan, Charles K. Toth, Topographic Laser Ranging and Scanning, 2017
Orthophoto production focuses on the elimination of the sensor tilt and terrain relief effects from captured perspective imagery. Uniform scale and the absence of relief displacement make orthophotos an important component of GIS databases, in which the user can directly determine geographic locations, measure distances, compute areas, and derive other useful information about the area in question. Recently, with the increasing availability of overlapping LiDAR and photogrammetric data, which is acquired from aerial and satellite imaging platforms, there has been a persistent need for an orthophoto generation methodology that is capable of dealing with the imagery acquired from such systems. Moreover, the increasing resolution of available data mandates the development of true orthophotos, in which occluded portions of the LiDAR surface are reliably detected in the involved imagery.
Scan-to-BIM method in construction: assessment of the 3D buildings model accuracy in terms inventory measurements
Published in Building Research & Information, 2022
Izabela Skrzypczak, Grzegorz Oleniacz, Agnieszka Leśniak, Krzysztof Zima, Maria Mrówczyńska, Jan K. Kazak
Two methods that may help resolve the above problems are 3D laser scanning and close-range photogrammetry using unmanned aerial vehicles (UAVs), which are increasingly applied in construction, architecture, land surveying and spatial planning. The obtained images and point clouds are used to create orthophoto that can become a basis for developing numerical terrain models (Anderson & Gaston, 2013), zone monitoring (Burdziakowski, 2017), an inspection of the hydrotechnical equipment technical condition and structures, updating information on agricultural and forest areas (Duffy et al., 2018) and investigating the pollutant distribution (Zheng et al., 2021). Further point clouds use is checking property tax declarations and determining road traffic intensity (Helman et al., 2018). In construction, architecture and spatial planning, low-altitude photogrammetry images acquired by drones are used during the construction and operation of engineering structures to capture difficult-to-reach surfaces and capacity objects, e.g. for record-keeping of roofs (including asbestos), cooling towers, tower blocks, dumping grounds and landfills (Khan et al., 2018). The images provide information used in sustainable spatial planning and land development for investment projects (Reinoso et al., 2018). As-built and inventory documentation prepared based on measurements taken using scanner and UAV, vector graphics, 2D projections, views, CAD (Computer-Aided Design) models and BIM models can be represented. The created BIM model (created from a point cloud obtained as a result of scanning and processed with the use of specialist software) allows aims to conduct construction analyses, renovation planning and efficient management of the object and its parameters.
Bridge deck surface distress evaluation using S-UAS acquired high-spatial resolution aerial imagery
Published in Annals of GIS, 2023
Su Zhang, Susan M. Bogus, Shirley V. Baros, Paul R. H. Neville, Hays A. Barrett, Tyler Eshelman
In this step, the dense point cloud in the previous step is used to create a triangulated irregular network (TIN) mesh, which is then rasterized to create a DSM (a grid representation of the ground surface). The DSM will be used as a project surface during orthocorrection of the input aerial photos. At the completion of orthocorrection, aerial photos will be mosaicked to create an orthophoto, which is co-registered with the DSM. The orthophoto and DSM are generated in a single processing routine, and they can be exported as rasters (e.g. GeoTIFF). For this study, the exported orthophoto and DSM are at a spatial resolution of 0.005 m (Figure 3).