Differential Absorption Lidar at 1.67 µm for Remote Sensing of Methane Leakage

• Published in: Japanese Journal of Applied Physics 1999-01, Vol.38 (1R), p.110
• Main Authors: Kouki Ikuta, Kouki Ikuta, Noboru Yoshikane, Noboru Yoshikane, Nilesh Vasa, Nilesh Vasa, Yuji Oki, Yuji Oki, Mitsuo Maeda, Mitsuo Maeda, Michihiro Uchiumi, Michihiro Uchiumi, Youichirou Tsumura, Youichirou Tsumura, Jun Nakagawa, Jun Nakagawa, Noriyuki Kawada, Noriyuki Kawada
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.38.110

A differential absorption lidar (DIAL) for field monitoring of methane (CH 4 ) leakage at a wavelength of 1.67 µm was developed. Compared with traditional DIAL systems for environmental monitoring, this system has a higher distance resolution (∼15 m) for determining the leak position and a shorter detection range up to 500 m. First, considering appropriate design parameters, a theoretical simulation was performed to evaluate the sensitivity and the detectable range of the system. Based on the analytical simulation, a prototype DIAL system was constructed and the detection of CH 4 which had leaked into the atmosphere was demonstrated. The CH 4 leakage of 6000 ppm·m at a distance of 130 m was successfully detected. The detection limit was 1000 ppm·m. With the improvements in the light source and the detector system, the detectable boundary can be increased in the range from 90 to 540 m for a concentration of 1500 ppm·m.