Optimization Of Band-pass Filtering Parameters Of Pure Rotational Raman Lidar And Design Of New System

Recently, environmental problem has more and more effects on human residence and economic development. In order to enhance the capacity of atmospheric pollution inspection, researches on new inspection devices are required. Currently, as a efficient and rapid remote sensing technique, Lidar (Light Detection and Ranging) has been applied to monitor some atmospheric parameters. In all kinds of lidar, pure rotational Raman lidar has been used to measure atmospheric temperature effectively. Bandpass filtering technique is one of the key unit techniques in pure rotational Raman lidar for atmospheric temperature measurements, it has great effects on the temperature detection sensitivity and measurement precision of a practical Raman Lidar system. In this paper, a global optimization algorithm, simulated annealing algorithm is employed for the design of optimum band-pass filtering parameters such as central filtering wavelength, wavelength interval, filtering bandwidth, etc., and high temperature detection sensitivity which is 3-5 times higher than currently reported results is obtained theoretically. Furthermore, we employ acousto-optic tunable filter (AOTF) as narrow band-pass filter and high-speed single-channel wavelength scanner to propose a novel lidar system. This new technique can solve the problems of conventional pure rotational Raman lidar, such as low signal detection sensitivity, untunability of filtering parameters, and signal interference between detection channels. It can be expected that the research results in this paper will effectively promote the development and application of pure rotational Raman lidar technology.