Multi-wavelength backscatter measurement of clouds and aerosols using a white lidar system

• Main Authors: Fujita, Masayuki, Yamanaka, Chiyoe, Galvez, Maria Cecilia D., Vallar, Edgar A.
• Format: text
• Published: Animo Repository 2003
• Subjects: Clouds; Aerosols; Optical radar; Backscattering; Physics
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/5859
• Institution: De La Salle University

With the recent technology of the high-peak power femtosecond laser, white light continuum in atmospheric gas can be generated. In 1998, Rairoux et. al. had demonstrated the application of this novel light source for atmospheric remote sensing[l]. The broad spectrum of the white light, can be used for multi-wavelength lidar studies. The multi-wavelength lidar measurements have the capability of obtaining the wavelength dependence of the backscatter coefficients of aerosols, which can be used to evaluate the particle size, and determine its size distribution [Z]. In this paper, application of white light lidar system for the multi- wavelength backscatter measurements of clouds and aerosols will be presented. The white light continuum was generated by a focused 0.8TWll00fs laser pulse in a 9-m long gas cell filled with atmospheric krypton rare gas which generated a broad spectrum of the white light, from 300 nm to 950 nm (Fig.1). We transmitted the white light to the atmosphere (Fig.2) and measured the backscattered light simultaneously with 4 channels of photomultipliers, which had different spectral filters. We observed the temporal evolution of the backscattered coefficient (Fig.3) and analyzed the particle size distribution.