Evaluation of Unmanned Aerial Vehicle (UAV) Data Accuracy for the Surveying Profession

Tingle, Leigh Robert James (2017) Evaluation of Unmanned Aerial Vehicle (UAV) Data Accuracy for the Surveying Profession. [USQ Project]


Affordable and readily accessible small-scale rotary Unmanned Aerial Vehicle (UAV) systems combined with accompanying software, have provided enthusiasts and professionals an opportunity to showcase, and even sell data and imagery to a third party without consultation from a Surveying professional. In addition, affordable access to survey grade hardware such as GNSS rovers has provided the user an ability to geo-reference the output data from the UAV, and provide ‘spatially corrected’ Digital Elevation Models (DEM) to third parties without an appropriate understanding, or appreciation of the procedures and limitations of the data when combined with the use of various systems as mentioned above. A misunderstanding of the limitations of the data could have undesirable flow on effects in design or construction stages of projects which rely on the accuracy of the original data set.

The author of the paper has investigated the limitations and achievable 3-dimensional point accuracies of various surface types and features in a typical urban environment, when utilising the data output from a professional grade multi rotor Unmanned Aerial Vehicle (UAV).

Built upon research and previous studies of the rotary UAV system, two test flights have been conducted by flying the drone at 15m and 40m above the highest point of the test site. The two test flights were then reduced independently utilising control points measured from two systems, one being the baseline measurements from a standard total station, the other from measurements using a Real Time Kinematic (RTK) rover connected to the Continuously Operating Reference System (CORS).

The information was reduced to orthomosaic images before being interrogated for point accuracy. The two sets of field data were geo-referenced using both the baseline total station control points, and the RTK control points, thus delivering four (4) sets of data for comparison. Each surface type point was compared with the baseline information, as well as each data set for comparison, to determine the achievable accuracy of each surface type measured with a UAV whilst the system is used in each circumstance.

The results from the field tests showed consistent surface types such as concrete, driveways, and bitumen surfaces returning favourable measurements with 0.010m ±0.006m achievable in vertical heights. Other surfaces such as grass and vegetation returned mixed results dependant on the height of the vegetation, and structures and features <0.2m wide such as fencing and trees, returned unreliable results. The overall results comparing Total Station and GNSS survey control provided minimal differences in both vertical and horizontal, where the user could expect vertical changes in the order of -0.009m ±0.003 between the two systems when used under the tested conditions. Various additional discoveries were made during the testing such as offsets to buildings, and appropriate error factors that need to be considered at various flight heights.

The test results of the various surface heights provide the reader with a broad range of achievable accuracies from various flight heights against the various surface types typically found in an urban environment and the limitations of each surface type when compared against the various flight heights. The paper also provides the reader with recommendations as to the appropriate uses of the system under various circumstances, and the errors that are expected to occur.

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Item Type: USQ Project
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: Liu, Xiaoye
Date Deposited: 13 Sep 2022 01:49
Last Modified: 13 Sep 2022 01:49
Uncontrolled Keywords: Unmanned Aerial Vehicle (UAV); surveying; evaluation; data accuracy
URI: https://sear.unisq.edu.au/id/eprint/40916

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