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© Geoinformatics International. Platform instability is one of the sources of error of Digital Elevation Model (DEM) derived from a low altitude aircraft. This paper examines the influence of atmospheric pressure (AP) on the DEM produced by drone system. To achieve the research objective, an experimental-based ftxed-wing drone platform was set up at the Universiti Putra Malaysia Campus. First, Ground Control Points (GCPs) and CheckPoints (CPs) were established within the study area by a real-time kinematic differential global positioning system. The drone flew seven times at different altitudes over the study area. In the process, an on-board canon digital camera took a series of overlapping photos. The photos were processed with an image-matching algorithm. Then orthorectified the photos using the GCPs. Photo orthorectification entails orientation of aerial photos with respect to the ground control points. It helps to remove distortions that might occur while acquiring or Processing the aerial photographs. In the end, seven DEMs were exported in tiff file format. Analysis of impact of AP on the resulting DEMs was conducted using a proposed model and obtained 0.072m, 0.05m, 0.014m, 0.0lm, 0.004m, 0.003m, and 0.002m for lOOm, I50m, 200m, 250m, 350m, 400m, and 500m altitudes, respectively. To confirm the efficiency of the proposed model, the results were tested using the CPs and their corresponding points on the DEMs and obtained root mean square error of 0.03m, O.OSm, 0.07m, O.lm, 13m, 0.14m, and 0.16m. On a final note, a close look at the validation and impact of AP results unveils a small gap. Hence, suggests that platform instability should be ignored amidst of other externai forces that can influence the performance of drone system. |
