Development of laser frequency monitoring system for measuring absolute vertical wind with a resonance scattering lidar

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K13575
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Space and upper atmospheric physics
• Research Institution: National Institute of Polar Research
• Principal Investigator: Ejiri Mitsumu K. 国立極地研究所, 研究教育系, 助教 (80391077)
• Co-Investigator(Renkei-kenkyūsha): NAKAMURA Takuji 国立極地研究所, 研究教育系, 教授 (40217857) ; ABO Makoto 首都大学東京, システムデザイン研究科, 教授 (20167951) ; NISHIYAMA Takanori 国立極地研究所, 研究教育系, 助教 (00704876) ; TSUDA Takuo 電気通信大学, 情報理工学研究科, 助教 (90444421)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 鉛直風 / 共鳴散乱ライダー観測 / 中間圏・下部熱圏領域 / 光ヘテロダイン干渉法

Outline of Final Research Achievements

Vertical wind in the mesosphere and lower-thermosphere (MLT) region is quite important for understanding interactions between the earth’s atmosphere and geospace. Only resonance scattering lidar can measure vertical distributions of the vertical winds, and its measurements require precise absolute value of transmitter laser frequency. We applied optical heterodyne method to develop a monitoring system of beat signals generated by frequency differences between transmitter laser pulse and well calibrated seeder laser (cw). The monitoring system design was improved and built into a resonance scattering lidar system. As a result, absolute vertical wind can be measured within accuracy of ~5 m/s. Using the developed lidar system, we will challenge measuring relatively strong vertical winds that are generated associated with aurora activities in the MLT region in the high latitudes.

Free Research Field

超高層大気科学