Faculty of Agriculture, Niigata University, 8050 Ikarashi 2-Nocho, Niigata, 950-2181, Japan.
Graduate School of Technology, Industrial, and Social Sciences, Tokushima University, 2-1 Minamijosanjima, Tokushima, 770-8506, Japan.
Sci Rep. 2024 Sep 29;14(1):22559. doi: 10.1038/s41598-024-73198-x.
Radar is a powerful technology for surveys of avian movements. Validating the accuracy of radar detection is essential when establishing quantitative criteria for tracking bird trajectories and counting bird flocks. This study clarifies the positional and biological factors influencing the probability of detection (POD) and echo size on X-band marine radar. The bird trajectory for validation was obtained by ornithodolite at the same time as the radar scan. Distance was found to have a negative effect on POD and echo size, while elevation angle positively affected POD. Body mass and flock size positively affected POD and echo size. In predicting detection performance, the survey distance required to achieve 50% POD was 750 m or less for Grey-faced Buzzard, the lightest target species, but up to 1800 m for a pair of Bewick's Swan. Our study provides survey and analysis procedures that allow for efficient validation using ornithodolites. Then, we identify the range settings that should be considered for target species and contribute to establishing criteria for quantitative radar bird surveys.
雷达是一种强大的鸟类运动调查技术。在建立跟踪鸟类轨迹和计数鸟类群的定量标准时，验证雷达探测的准确性至关重要。本研究阐明了影响 X 波段海洋雷达探测概率（POD）和回波大小的位置和生物学因素。验证用的鸟类轨迹是在雷达扫描的同时用鸟类定向仪获得的。距离对 POD 和回波大小有负面影响，而仰角对 POD 有正面影响。体重和鸟群大小对 POD 和回波大小有正面影响。在预测探测性能时，对于最轻的目标物种灰脸鵟鹰，达到 50% POD 所需的调查距离为 750 米或更短，但对于一对黑嘴天鹅，需要长达 1800 米。本研究提供了使用鸟类定向仪进行高效验证的调查和分析程序。然后，我们确定了应考虑的目标物种的范围设置，并有助于建立定量雷达鸟类调查的标准。
