[OPTICAL REVIEW Vol. 17, No. 2 (2010) 84-89]
© 2010 The Japan Society of Applied Physics

Spectrum Characteristics of Multichannel Water Raman Lidar Signals and Principal Component Analysis

Dukhyeon KIM*, Imkang SONG1, Hai-Du CHEONG, Yonggi KIM1, SungHun BAIK2, and Jeongsoon LEE3

Hanbat National University, College of Humanities and Sciences, Daejeon 305-719, Korea
1Department of Physics, Kongju National University, Gongju 314-701, Korea
2Laboratory for Quantum Optics, Daejeon 305-600, Korea
3Environment Measurement Group, Korea Research Institute of Standard and Science (KRISS), Daejeon 305-600, Korea

(Received October 17, 2009; Accepted February 3, 2010)

Using a multichannel full Raman lidar, water Raman signals composed of 32 different Raman wavelengths were obtained, and the time and cloud-height dependences of each spectrum on clear and cloudy days were determined. Although the Raman signals of winter cloud have a higher intensity at short wavelengths than those of summer cloud, these two types of clouds have large overlapping regions in wavelength space. However, in eigenvector space, winter and summer clouds are located at different points and have no overlapping regions. We have suggested that, as a cloud Raman lidar, a multiple-wavelength Raman lidar must be used, and the principal component analysis (PCA) method should be applied to determine the relative amount of each water phase.

Key words: liidar, Raman scattering, liquid water, water vapor, ice water, eigenvector, principal component analysis

*E-mail address: dhkim7575@paran.com