Three-Dimensional Shape and Fall Velocity Measurements of Snowflakes Using a Multiangle Snowflake Imager
Three-Dimensional Shape and Fall Velocity Measurements of Snowflakes Using a Multiangle Snowflake Imager
复制标题
使用多角度雪花成像仪测量雪花的三维形状和下落速度
DOI：
10.1175/jtech-d-16-0221.1
复制
发表时间：
2017
影响因子：
2.2
通讯作者：
Fujiyoshi Yasushi
中科院分区：
文献类型：
--
作者：
Minda Haruya;Tsuda Norio;Fujiyoshi Yasushi
本文介绍了一种多角度雪花成像仪（MSI），旨在捕捉伪三维（3D）的形状和单个雪花的大小大于1.5毫米的下降速度。四个高度偏移线图像扫描仪估计下落速度和四个角度的轮廓被用来重建三维雪花形状。使用参考对象（球体、椭球体、立方体和板）测试3D形状重建。MSI的四轮廓方法与两轮廓方法（例如二维视频转速计（2DVD））相比改进了颗粒形状和体积的表示。由四轮廓方法估计的雪花的体积（等体积直径）比由两轮廓方法估计的小约44%（13%）。通过与2DVD在三个降雪事件的比较，验证了成像仪的能力，以测量的下降速度和颗粒尺寸分布的基础上的轮廓宽度和3D形状的颗粒的等体积直径。
This paper describes a Multiangle Snowflake Imager (MSI) designed to capture the pseudo-three-dimensional (3D) shape and the fall velocity of individual snowflakes larger than 1.5 mm in size. Four height-offset line-image scanners estimate fall velocities and the four-angle silhouettes are used to reconstruct the 3D snowflake shapes. The 3D shape reconstruction is tested using reference objects (spheres, spheroids, cubes, and plates). The four-silhouette method of the MSI improves the representation of the particle shape and volume compared to two-silhouette methods, such as the two-dimensional video disdrometer (2DVD). The volume (equivolumetric diameters) of snowflakes estimated by the four-silhouette method is approximately 44% (13%) smaller than that estimated by the two-silhouette method. The ability of the imager to measure the fall velocity and particle size distributions based on the silhouette width and the equivolumetric diameter of 3D-shaped particles is verified via a comparison with the 2DVD in three snowfall events.