Development of a radiative transfer model and laboratory pressure-broadening measurements for understanding terahertz radiation processes in planetary atmospheres.

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K13985
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 17010:Space and planetary sciences-related
• Research Institution: National Institute of Information and Communications Technology
• Principal Investigator: Yamada Takayoshi 国立研究開発法人情報通信研究機構, テラヘルツ研究センター, 主任研究員 (00852261)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: テラヘルツ波 / 電磁波伝搬

Outline of Final Research Achievements

Terahertz-wave remote-sensing for planetary atmospheres can be carried out with passive day/night observations and high spatial and frequency resolution. Analysis of its observed spectra requires a radiative transfer model, the accuracy of which also depends on the accuracy of the spectral parameters. In this study, the construction of a gas spectroscopy system in the 220-500 GHz band using a terahertz wave transmitter/receiver has been completed, enabling high-precision frequency resolution and simple bandwidth setting. The development of an electromagnetic wave propagation model and inverse analysis algorithm for the Martian atmosphere has also been completed, enabling the derivation of atmospheric vertical profiles from observed spectra and their vertical resolution and error evaluation using absorption intensity and pressure width parameters obtained in the laboratory.

Free Research Field

惑星科学

Academic Significance and Societal Importance of the Research Achievements

今後テラヘルツ波帯での分光観測機会が増加する中、高精度な観測に加え、高精度な圧力幅定数などの分光パラメータも重要となる。本研究では220－500GHzでの広帯域なガス分光測定を開発したことにより、測定データが不十分だった吸収線パラメータの取得が可能になった。