Significance of the extinction to backscatter ratio and the boundary value term in characterizing the aerosol/cloud layers obtained at a coastal station in Trivandrum, India

Autor: Mohankumar Santhibhavan Vasudevan Pillai, Muraleedharen Nair Sivaramapillai, Presennakumar Bhargavan, Sreeja Rajappan, Duggirala Ramakrishna Rao, Malladi Satyanarayana
Rok vydání: 2006
Předmět:
Zdroj: SPIE Proceedings.
ISSN: 0277-786X
DOI: 10.1117/12.694035
Popis: Laser Radar-Lidar has been established as a promising tool in the remote sensing of aerosols and cloud layers in the atmosphere and in obtaining the altitude profiles of aerosol extinction coefficient. A variety of inversion methods have been used to obtain the altitude profiles of extinction / backscattering coefficients of the aerosols from the Mie lidar signals. Fernald's method which offers a general solution for the two component atmosphere involving aerosols and molecules is widely used to obtain the altitude profile of aerosol extinction coefficient and backscattering coefficient. This solution is most sensitive to the Boundary value at the calibration level and the aerosol extinction to backscattering ratio. In this paper the sensitivity of the above mentioned parameters on the live lidar data obtained from the tropical coastal station Trivandrum is investigated. In the following some numerical calculations are also carried out confining the situation to lidar measurements in the horizontal direction in order to investigate the significance of extinction to backscatter ratio and boundary value term in the solution for the two component lidar equation. This analysis is carried out at various altitude regions under different turbidity conditions in order to obtain a profile for the aerosol extinction to backscatter ratio for which the solution is less sensitive. Hence a new inversion method is proposed in the following using this variable lidar ratio at each altitude while inverting the lidar signal so that the possible error can be minimized.
Databáze: OpenAIRE