Video-Based Estimation of Surface Currents Using a Low-Cost Quadcopter
Video-Based Estimation of Surface Currents Using a Low-Cost Quadcopter
复制标题
使用低成本四轴飞行器基于视频的表面电流估计
DOI：
10.1109/lgrs.2017.2749120
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发表时间：
2017
影响因子：
4.8
通讯作者：
J. Horstmann
中科院分区：
文献类型：
--
作者：
M. Stresser;R. Carrasco;J. Horstmann
从一个小型的现成的四轴飞行器与自稳定相机万向节记录的表面波的视频图像进行分析，以估计表面电流场。最低点摄像机获取一个短的图像序列，该图像序列被地理编码为通用横轴墨卡托坐标。由此产生的图像序列被用来量化的特征参数（波长，周期和方向）的短（0.1-1米）表面波在空间和时间。这为将线性色散关系拟合到数据提供了机会，从而监测由环境电流引起的频移。通过在波数-频率域中应用基于谱能量的最大化技术来执行拟合。的电流场与声学多普勒海流剖面仪安装在一艘小船上获得的测量值进行了比较，显示出整体良好的协议。在没有偏差的情况下，流速的均方根误差为0.09 m/s。
Video imagery of surface waves recorded from a small off-the-shelf quadcopter with a self-stabilizing camera gimbal is analyzed to estimate the surface current field. The nadir looking camera acquires a short image sequence, which is geocoded to Universal Transverse Mercator coordinates. The resulting image sequence is used to quantify characteristic parameters (wavelength, period, and direction) of short (0.1–1 m) surface waves in space and time. This opens the opportunity to fit the linear dispersion relation to the data and thus monitor the frequency shift induced by an ambient current. The fitting is performed by applying a spectral energy-based maximization technique in the wavenumber–frequency domain. The current field is compared with measurements acquired by an acoustic Doppler current profiler mounted on a small boat, showing an overall good agreement. The root-mean-square error in current velocity is 0.09 m/s with no bias.