Dear colleagues, We are pleased to announce the publication of our paper in Marine Mammal Science:
Burnett, J. D., Lemos, L., Barlow, D. R., Wing, M. G., Chandler, T. E., Torres, L. G. (2018). Estimating morphometric attributes of baleen whales with photogrammetry from small UAS: a case study with blue and gray whales. Marine Mammal Science. doi:10.1111/mms.12527 ABSTRACT: Small unmanned aircraft systems (sUASs) are fostering novel approaches to marine mammal research, including baleen whale photogrammetry, by providing new observational perspectives. We collected vertical images of 89 gray and 6 blue whales using low cost sUASs to examine the accuracy of image based morphometry. Moreover, measurements from 192 images of a 1 m calibration object were used to examine four different scaling correction models. Results indicate that a linear mixed model including an error term for flight and date contained 0.17 m less error and 0.25 m less bias than no correction. We used the propagation uncertainty law to examine error contributions from scaling and image measurement (digitization) to determine that digitization accounted for 97% of total variance. Additionally, we present a new whale body size metric termed Body Area Index (BAI). BAI is scale invariant and is independent of body length (R2 = 0.11), enabling comparisons of body size within and among populations, and over time. With this study we present a three program analysis suite that measures baleen whales and compensates for lens distortion and corrects scaling error to produce 11 morphometric attributes from sUAS imagery. The program is freely available and is expected to improve processing efficiency and analytical continuity. The full article is open access, and is available online: https://onlinelibrary.wiley.com/doi/full/10.1111/mms.12527 Furthermore, the code for the analysis programs are freely available, and can be accessed via the supplemental materials. Cheers, Dawn Dawn Barlow PhD Student Department of Fisheries and Wildlife, Marine Mammal Institute Oregon State University, Hatfield Marine Science Center Geospatial Ecology of Marine Megafauna Lab<https://mmi.oregonstate.edu/gemm-lab> dawn.bar...@oregonstate.edu
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