Remote measurement of volcanic gas profile by portable lidar

2020 Fiscal Year Final Research Report

• Project/Area Number: 18H01667
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 25020:Safety engineering-related
• Research Institution: Tokyo Metropolitan University
• Principal Investigator: Shibata Yasukuni 東京都立大学, システムデザイン研究科, 准教授 (10305419)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: ライダー / SO2 / 差分吸収 / 火山ガス

Outline of Final Research Achievements

The purpose of this study is to manufacture a lidar system for measuring SO2 concentration in volcanic gas and to demonstrate its usefulness by field observation. We have developed a light source based on two Nd: YVO4 lasers.
An indoor SO2 gas concentration measurement experiment was conducted, and it was shown that measurement was possible at 0.35±0.06 ppm (±17.1%). The result was that it was possible to measure within ±1ppm, compared to 5ppm, which is said to cause harm to the human body. Due to the delay in laser development and social factors caused by the COVID-19, field experiments could only be performed twice, and valid data could not be obtained.

Free Research Field

リモートセンシング

Academic Significance and Societal Importance of the Research Achievements

現状、直接センサを用いてガス濃度を計測する手法が主流であり、平面分布を得るには多数のセンサが必要となる。また、紫外光に感度のあるCCDカメラでSO2の吸収帯に当たる波長（～310 nm）とSO2の吸収帯からずれた波長（～330 nm）を撮像し、光の吸収量の差からSO2カラム量分布イメージを遠隔計測する手法は空間分布を得ることができない。本研究の成果は、SO2ガス分布の空間分布計測が可能であることを示すものであり、火山ガス分布の状況をリアルタイムで把握することで、防災・減災のみならず、経済活動への影響を最小限に抑えることが期待できる。