CREATING ACCURATE DIGITAL SURFACE MODELS USING UAV MOUNTED COMMERCIAL GRADE CAMERAS: A PRACTICAL METHODOLOGY TO GENERATE MAP QUALITY GEOREFERENCED IMAGERY AND TOPOGRAPHY
We have demonstrated this capability using a sample of UAV based imagery of the Djarrit section of Majuro, Republic of the Marshall Islands collected in September, 2016. The collected imagery (537 vertical photographs) was processed and refined to produce a bare-earth digital elevation model with a horizontal RMSE of 0.69 m and a vertical accuracy of 0.3 m (L.E. = 0.28 m) and final orthomosaics with a pixel resolution of resolution of 0.25 m. This level of accuracy was achieved using an integrated ground-aerial planning methodology that included placed ground targets, survey-grade and kinematic GPS surveys and an iterative post-processing workflow that moved away from relying on inaccurate UAV-based GPS. We will present these results and outline a field-work plan and methodology that we hope will aid other researchers.