Quihampton, William (2017) The effect of flight height, image overlap and the number of GCPs used on the accuracy of an aerial photogrammetry survey over a road surface, with an assessment of the suitability of aerial photogrammetry for road conformance testing. [USQ Project]
Abstract
In recent years aerial photogrammetry has rapidly developed to a point where it is now considered a viable tool for use in different areas of surveying. This development has been facilitated through improvements in digital cameras, aerial platforms and computer systems. As beneficial as this development appears to have been it has resulted in considerable knowledge gaps emerging relating to the accuracies that are achievable and the technologies’ suitability to different applications.
There are a number of variables that can impact the accuracy of an aerial photogrammetry project with the impact of these variables not yet being completely understood. This project investigates the impact of the variables of; flight height, image overlap and the number of GCPs used on the vertical accuracy of an aerial photogrammetry survey over a road surface. The investigation of these parameters has been used to determine if aerial photogrammetry is a tool that could be used in road conformance testing.
This project used a DJI Phantom 4 Pro UAV to fly five data acquiring flights, of varying height and image overlap over an existing road. The data collected was processed using the photogrammetry software Pix4D. The collected data was processed and analysed resulting in the following findings; • A 10 m change in flight height caused a changed in a change in vertical accuracy in the vicinity of 30 mm • The impact of image overlap could not definitively be established using the methodology outlined in this report • An increase in the number of GCPs used resulted in an improved accuracy, however there was a diminishing rate of improvement with respect to the number GCPs used.
Based on the literature review undertaken and the results obtained as part of this project, aerial photogrammetry has been found to be unsuitable for the purpose of road conformance testing. This finding is based on the accuracies that are achievable, aerial photogrammetry’s suitability to different sites and the time required to undertake and process the collected data.
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| Item Type: | USQ Project |
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| Item Status: | Live Archive |
| Additional Information: | Bachelor of Spatial Science (Honours) (Surveying) |
| Faculty/School / Institute/Centre: | Historic - Faculty of Health, Engineering and Sciences - School of Civil Engineering and Surveying (1 Jul 2013 - 31 Dec 2021) |
| Supervisors: | Chong, Albert Kon-Fook |
| Date Deposited: | 13 Sep 2022 03:22 |
| Last Modified: | 13 Sep 2022 03:22 |
| Uncontrolled Keywords: | aerial photogrammetry; surveying tool; accuracy; road conformance testing |
| URI: | https://sear.unisq.edu.au/id/eprint/40927 |
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