简介
Two-Dimensional Video Disdrometer (2DVD)
测距仪是一种安装在固定地面站平台上的光学设备，用于测量不同类型水文流星（降水）的特性，如雨滴、雪花和冰雹。二维视频测距仪 (2DVD) 使用两台高速线扫描照相机对所有降水颗粒和类型的大小分布、形状和下落速度进行连续测量。前言 – 人工智能教程
由两个内部灯管提供的两个光平面穿过约 10x10 厘米的虚拟测量区域，并投射到两个高速线扫描相机上。落在光平面上的水介质会投下阴影，由仪器内部的两台相机记录下来。光平面之间有一个校准距离，可以测量落下粒子的速度。线扫描照相机每 18 微秒对每个平面进行采样；因此，当水流星落过测量区域时，每个图像的多个线扫描会从两个侧面和两个不同高度记录下来，以便进行精确测量。
获得的数据包括水滴大小分布、降雨率、降雨速度、降水类型、水滴大小。 2DVD 仪器在测量方面有一定的局限性，例如只能测量一定大小或一定速度范围内的水滴。
昆虫、飞溅的水滴和同时落在摄像头之间的多个水滴都会影响这些测量的准确性，这需要通过质量控制措施来解决。 如果 2DVD 测滴仪在一次测量中未能收集到 20% 或更多的测量数据，则所收集的数据将被视为无效数据。
数据下载链接
Instrument: 2DVD Disdrometer | Global Hydrometeorology Resource Center (GHRC)
数据属性
| SPATIAL RESOLUTION | SPATIAL EXTENT | TEMPORAL RESOLUTION | ACCURACY OF RAIN RATE MEASUREMENTS | SAMPLING DURATION/DWELL TIME |
|---|---|---|---|---|
| 200 micrometer | point | Per rain event | ±0.45 mm | 18 microseconds |
代码：
!pip install leafmap
!pip install pandas
!pip install folium
!pip install matplotlib
!pip install mapclassifyimport pandas as pd
import leafmapurl = "https://github.com/opengeos/NASA-Earth-Data/raw/main/nasa_earth_data.tsv"
df = pd.read_csv(url, sep="\t")
dfleafmap.nasa_data_login()results, gdf = leafmap.nasa_data_search(short_name="2dimpacts",cloud_hosted=True,bounding_box=(-75.4912, 37.9194, -75.4462, 37.9543),temporal=("2020-01-15", "2020-02-28"),count=-1, # use -1 to return all datasetsreturn_gdf=True,
)gdf.explore()#leafmap.nasa_data_download(results[:5], out_dir="data")结果
引用
Grazioli, J., D. Tuia, S. Monhart, M. Schneebeli, T. Raupach, and A. Berne (2014): Hydrometeor classification from two-dimensional video disdrometer data. Atmospheric Measurement Techniques, 7, 2869-2882. doi: AMT - Hydrometeor classification from two-dimensional video disdrometer data
Jaffrain, J., A. Studzinski, and A. Berne (2011): A network of disdrometers to quantify the small-scale variability of the raindrop size distribution. Water Resour. Res., 47, W00H06, doi: http://dx.doi.org/10.1029/2010WR009872
Kathiravelu, Gopinath, Terry Lucke, and Peter Nichols (2016): Rain Drop Measurement Techniques: A Review. Water, 8 (29), 1-20. doi: Water | Free Full-Text | Rain Drop Measurement Techniques: A Review
Kruger, A. and W. F. Krajewski (2002): Two-Dimensional Video Disdrometer: A Description, Journal of Atmospheric and Oceanic Technology, 19, 602-617. doi: Two-Dimensional Video Disdrometer: A Description in: Journal of Atmospheric and Oceanic Technology Volume 19 Issue 5 (2002)
Schönhuber, M., G. Lammer, and W. L. Randeu (2008): The 2D-video-disdrometer, Precipitation: Advances in Measurement, Estimation and Prediction. S. Michaelides, Ed., Springer, 3-31. doi: The 2D-Video-Distrometer | SpringerLink
Tokay, A., A. Kruger, and W. Krajewski (2001): Comparison of drop size distribution measurements by impact and optical disdrometers. J. Appl. Meteor., 40, 2083–2097. doi: Comparison of Drop Size Distribution Measurements by Impact and Optical Disdrometers in: Journal of Applied Meteorology and Climatology Volume 40 Issue 11 (2001)
