Interpolated satellite tracking data - Dugong dugon - New Caledonia - 2012-2019

Interpolated dugong GPS tracks recorded in 2012, 2013 and 2019 over the west coast of New Caledonia, South Pacific. GPS locations were filtered to remove invalid locations of uncertain QFP and unresolved QFP and locations implying unrealistically rapid movements (speed > 10 km/h). When a track was interrupted for more than 10 hours, the track was considered to be constituted by several segments, which were subsequently modeled separately. Track segments were projected in a UTM coordinate system and were interpolated hourly with a Continuous-time Correlated Random Walk (CRW) model using the "crawl" R package (version 2.2.3). Residence time was calculated along the crawl-interpolated tracks to assess movement type (higher values indicating Area Restricted Search when animals slow down and display more sinuous paths). Tidal cycle data were acquired for each hourly dugong position from in situ tide gauge measurements at the Numbo station in Nouméa, New Caledonia (REFMAR, data.shom.fr). Dial cycle was approximated by dividing days into four phases: dawn (3 a.m – 9 a.m), day (9 a.m – 3 p.m), dusk (3 p.m – 9 p.m) and night (9 p.m – 3 a.m).

本数据集收录了2012年、2013年与2019年在南太平洋新喀里多尼亚西海岸记录的儒艮（Dugong）插值GPS轨迹数据。对其中的GPS定位点进行滤波处理，以移除不确定性QFP、未解析QFP以及运动速度超过10 km/h的不合理快速移动点位。当单条轨迹中断时长超过10小时时，该轨迹将被拆分为多个分段，并分别开展建模工作。将轨迹分段投影至通用横轴墨卡托（Universal Transverse Mercator, UTM）坐标系下，随后采用R包"crawl"（版本2.2.3）中的连续时间相关随机游走（Continuous-time Correlated Random Walk, CRW）模型，以每小时为间隔进行插值处理。基于经crawl包插值得到的轨迹计算停留时间，以此判别儒艮的运动类型：当儒艮运动速度放缓、路径更趋蜿蜒时，停留时间数值会升高，此时对应区域限制搜索（Area Restricted Search, ARS）行为。针对每小时一次的儒艮定位点位，从新喀里多尼亚努美阿市Numbo站的原位潮位计测量数据中获取潮汐周期数据，数据源为REFMAR与data.shom.fr。日光照周期通过将单日划分为四个时段进行近似划分：黎明（3:00 - 9:00）、白天（9:00 - 15:00）、黄昏（15:00 - 21:00）与夜间（21:00 - 3:00）。