Assessing optimal UAV-data pre-processing workflows for quality ortho-image generation to support coral reef mapping. Issue 25 (13th December 2022)

• Record Type: Journal Article
• Authors: Zaki, Nurul Hidayah Mat; Chong, Wei Sheng; Muslim, Aidy M.; Reba, Mohd Nadzri Md; Hossain, Mohammad Shawkat
• Is Part Of: Geocarto international. Volume 37:Issue 25(2023)
• Page Start: 10556
• Page End: 10580
• Publication Date: 2022-12-13
• Subjects: DJI Matrice -- multispectral UAV -- MicaSense -- Pulau Bidong -- South China Sea; Remote sensing -- Periodicals; Geographic information systems -- Periodicals; Geology -- Periodicals; Cartography -- Periodicals; 621.3678
• DOI: 10.1080/10106049.2022.2037732
• Languages: English
• ISSNs: 1010-6049

Abstract

Abstract: Since ortho-image constructed from unmanned aerial vehicles (UAV) acquired images has significant misalignment effect, an optimized and precise workflow (WF) is proposed in this study. Based on the parameters of photo alignment, sparse point cloud model, blending and seamline refinement, the 24 combinations of ortho-image producing methods were tested. The optimal WF is evaluated from the aspects of coral mapping accuracy, geometric fidelity, completeness, and efficiency. Statistical error analysis shows that blending and seamline refinement are the most relevant WF components that influence accuracy of orthorectification and consequently coral reef classification. The optimal WF found to be when 'highest' photo alignment, with 'high' tie points in the sparse cloud model are applied, in presence of blending and seamline refinements and can achieve 87.9% overall mapping accuracy. With the available photogrammetric software packages, the proposed WF can be used in mosaicking and mapping large scale macroalgae, seagrass and seaweed.