[H-DS13] [EE] Remote Sensing of Natural Hazards and Mitigation of Impacts on Human/Ecosystem

[HDS13-P04] 吹雪の稠密観測を目指した低価格視程計の性能評価

*小林 ゆい¹、渡辺 恭也¹、川俣 大志^1,2、成瀬 延康³、根本 征樹⁴、西村 浩一⁵、高橋 幸弘^1,6 (1.北海道大学グローバルサイエンスキャンパス、2.北海道大学高等教育推進機構、3.滋賀医科大学、4.防災科学技術研究所雪氷防災研究センター、5.名古屋大学大学院環境学研究科、6.北海道大学大学院理学研究院)

キーワード：Blowing snow, Disaster Prevention, Instrument Development

In our previous study, we developed a low-cost poor-visibility meter (~\500,00) for hyper-densely observation of blowing snow. Our developed instrument works as a reduced intensity of light when snow particles block off. We used semiconducting laser for the light source (~\500). The laser beam is reflected three times by using mirrors and it enables us to make compact instrument with enough length of light path. Our developed system has a capability of extending a hyper-densely observation in real-time using wireless network. Our study aims performance evaluation of the low-cost poor-visibility meter for hyper-densely observation of blowing snow in the condition of artificial and natural one. We have checked the correlation between the reduced laser intensity taken by our system and the visibility recorded by conventional video camera simultaneously; the visibility corresponds to the pixel intensity obtained from the movie (1frame 1/30sec, 8-bit). Natural (Artificial) blowing snow was measured in Sapporo City (Cryospheric Environment Simulator of the Shinjo Branch, Snow and Ice Research Center, National Research Institute for Earth Science and Disaster Prevention in Shinjo city). The wind velocity was 10-15m/s and temperature was from -4℃ to -15℃. We have performed theoretical analysis for the relation between the laser intensity and the poor visibility based on our original formulation. The resultant value for the correlation coefficient in artificial blowing snow was 0.95. In conclusion, we have conducted the performance evaluation of the low-cost poor-visibility meter for hyper-densely observation of blowing snow, having a potential of hyper-densely monitoring on wireless network, and have made sure the practicability.