ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences (May 2019)
DETECTING ANTARCTIC SEALS AND FLYING SEABIRDS BY UAV
Abstract
In recent years Unmanned Aerial Vehicles (UAVs) became a fast-developing technology with manifold fields of application. In the field of wildlife biology, it offers the opportunity to quantify populations, to map the spatial distribution of species and to observe the behavior of animals with no or low disturbance. Moreover, UAV based mapping allows to obtain data from sites which are hardly or not accessible and to cover much larger areas than by traditional ground based methods. The advantages of UAV based mapping are of particular relevance under the harsh conditions of Antarctic fieldwork. Whether certain species qualify for UAV based monitoring depends on their detectability from the distance and the distinctiveness of their characteristics in comparison to other species, which has not been studied for Antarctic species in detail so far. This study aims to evaluate how and under which conditions, particularly flight height, Antarctic flying seabird and seal species are detectable in aerial imagery. A trial was conducted comparing the detection rate of different observers for several Antarctic species in aerial images of different ground sample distances. Descriptions of individual appearance as well as body size dimensions are delivered for all species. For most of the investigated species, monitoring proves to be possible from practical flight heights, while others are still very hard to detect even in low altitudes. A concluding table is given aiming to provide a guide for future surveys on which flight altitudes to chose and how to identify focal study objects.