Stratospheric DIAL system Maido 6 channels and 3 signal pairs of - PowerPoint PPT Presentation

Stratospheric DIAL system Maido 6 channels and 3 signal pairs of absorbed/non absorbed wavelength 4 rayleigh pairs and 2 raman pairs

DIAL METHOD nO3(z) ozone number density at altitude z P( λi ,z) number of detected photons at wavelength λ I ΔσO3 (z) corresponds to the differential ozone absorption cross-section σO3(λ 1 ,z) - σO3(λ 2 ,z) δnO3 (z) correction term depending on absorption by other constituents and Rayleigh and Mie differential Extinction P bi is the background number of photon at wavelength λ i ,

TREATEMENT • the lidar signals (individual file of 3 min) are time- averaged over the whole measurement period (3 h in general)  increase the signal-to-noise ratio. • Background correction • Correction of the saturation of the photon counting signals in the lower altitudes. • Correction from the Rayleigh extinction using composite pressure – temperature profiles from daily radiosoundings at gillot airport and model.

Typical resolution and precision