Evaluation of Lidar and Medium Scale Photogrammetry for Detecting Soft-Cliff Coastal Change |
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| Authors: | James Adams & Jim Chandler |
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| Institution: | University of Nottingham;, Loughborough University |
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| Abstract: | Lidar and photogrammetry have both been evaluated for detecting shortterm coastal change using the Black Ven mudslide, Dorset as a case study. A lidar-generated digital elevation model (DEM) was obtained and initially compared with a DEM generated using available 1:7500 scale aerial photography and automated digital photogrammetry. The quality of these two data sets was assessed using a third DEM, derived using a total station and conventional ground survey methods. The vertical accuracies (rms error) of the lidar and photogrammetry were 0.26m and 0.43m respectively, although both data sets displayed a tendency to generate heights slightly lower than the elevation of the terrain surface. The quality of the two data sets was then assessed with respect to local slope angle. The accuracy of photogrammetrically derived elevations varied with slope and more so than in the case of lidar
From these basic tests, lidar has proved to be more accurate than photogrammetry for soft-cliff. monitoring. Further research is required to establish whether this trend is applicable to other data sets and specifically for photogrammetric data acquired using larger scale imagery |
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| Keywords: | airborne laser scanning Black Ven mudslide digital photogrammetry landscape modelling lidar normal-angle (f=305 mm) photography |
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