Spectroscopic system design and analysis of solar-blind wavelength high spectral resolution Rayleigh lidar for atmosphere temperature measurement

All-time atmosphere temperature measurement is important for meteorology. High spectral Rayleigh Lidar at solar blind wavelength 266 nm is proposed to avoid solar background light of daytime and realize all-time atmosphere temperature profiling measurement. At the same time the Rayleigh scattering spectral width is broader and scattering intensity is stronger for 266 nm wavelength compared with 355 nm. Two Rayleigh scattering channel signals, which determine the atmosphere temperature, are filtered with two Fabry-Perot filters (Filter-1 and Filter-2) which located on the same side of the wings of the Rayleigh-scattering spectrum. Mie signal is detected with a third Fabry-Perot etalon filter (Filter-3), which is centered at the laser frequency. The Fabry-Perot filter parameters are optimized and analyzed by numerical calculation based on 266 nm wavelength. The FWHMs of Filter-1, Filter-2, Filter-3 respectively are 185 MHZ, 1 GHz, 285 MHz and their central relative frequencies respectively are 1.6 GHz, 3.5 GHz, 0 GHz. The Mie rejection of Filter-1 Rayleigh channel is up to 45 dB. The temperature measuring sensitivity is 0.49%/K (3 km). The system transmittance, SNR and temperature error are calculated and analyzed for different ozone concentrations. The results are shown that the temperature error is less than 1 K up to a height of 5.3 km at all time under the condition of 150 mJ laser energy, 400 mm receiver telescope and 40 ppb O-3 concentration.