Ocean hazardous spills and search and rescue incidents are becoming more prevalent as maritime activities increase across all sectors of society. However, emergency response time remains a factor due to the lack of information available to accurately forecast the location of small objects. Existing drifting characterization techniques are limited to objects whose drifting properties are not affected by on-board wind and surface current sensors. To address this challenge, we study the application of multirotor small unmanned aerial systems (sUAS), and embedded navigation technology, for on-demand wind velocity and surface flow measurements to characterize drifting properties of small objects. An off-the-shelf quadrotor sUAS was used to measure the speed and direction of the wind field at 10 m above surface level near a drifting object. We also leveraged sUAS-grade attitude and heading reference systems and GPS antennas to build water-proof tracking modules that recorded the position and orientation, as well of translational and rotational velocities, of objects drifting in water. The quadrotor and water-proof tracking modules were deployed during field experiments conducted in Claytor Lake, Virginia and the Atlantic Ocean south of Martha’s Vineyard, Massachusetts to characterize the leeway parameters of manikins that simulated a person in water. Leeway parameters were found to be an order of magnitude within previous estimates that were derived using conventional wind and surface current observations. We also determined that multirotor sUAS and water-proof tracking modules can provide accurate and high-resolution ambient information that is critical to understand how changes in orientation affect the downwind displacement and jibing characteristics of small objects floating in water. These findings support further development and application of multirotor sUAS technology for leeway characterization and understanding the effect of an object’s downwind-relative orientation on its drifting characteristics.

随着海上活动在社会各界的增加，海洋有害溢漏以及搜索和救援事件正变得越来越普遍。但是，由于缺乏可用于准确预测小物体位置的信息，因此紧急响应时间仍然是一个因素。现有的漂移表征技术仅限于其漂移特性不受车载风和地面电流传感器影响的物体。为了应对这一挑战，我们研究了多旋翼小型无人机系统（sUAS）和嵌入式导航技术在按需风速和地表流量测量中的应用，以表征小物体的漂移特性。使用现成的四旋翼sUAS来测量漂移物体附近地面以上10 m处的风场的速度和方向。我们还利用sUAS级姿态和航向参考系统以及GPS天线来构建防水跟踪模块，该模块可记录漂浮在水中的物体的位置和方向以及平移和旋转速度。在弗吉尼亚州的克莱托湖和马萨诸塞州玛莎葡萄园岛以南的大西洋进行的野外实验期间，部署了四旋翼和防水跟踪模块，以表征模拟人体在水中的人体模型的回旋参数。发现背风参数在以前的估计值范围内是一个数量级，该估计值是使用常规风和地表电流观测值得出的。我们还确定了多旋翼sUAS和防水跟踪模块可以提供准确和高分辨率的环境信息，这对于理解方向变化如何影响顺风向位移和漂浮在水中的小物体的起伏特性至关重要。这些发现支持多旋翼sUAS技术的进一步开发和应用，以进行风向表征，并了解物体的顺风相对方位对其漂移特性的影响。