DIN ISO 28902-4:2025-03 - Draft

This document describes the determination of height-resolved profiles of atmospheric backscattering by means of active optical sounding. The measurements allow the following properties of the atmosphere up to several kilometres above ground to be derived: - Cloud bases - Upper boundaries of optically thin clouds - Upper and lower boundaries and internal structures of particle layers: - The height of structures, e. g., inversions, boundary layer height, mixing layer height (under suitable conditions) - Attenuated backscatter of the particles - Backscatter coefficients of particles, extinction coefficients (requires further assumptions). The document goes on to discuss the depolarisation lidar and the use of multi-wavelength systems. This allows further parameters to be determined: - Particle size classification (Ångström exponent, colour ratio) - Shape classification (linear depolarisation degree) The following fields of application are particularly important: - Air quality monitoring (vertical structure of the boundary layer) - Aviation safety (cloud base and visual range) (see ISO 28902 Part 1) - Particle content and transport (e. g., volcanic dust) - Weather forecasting and climate modelling (e. g., atmospheric boundary layer, cloud base) - Satellite remote sensing (validation)

07.060, 13.040.20