Simulations of the retrieval of a two-dimensional wave-like structure in the atmospheric boundary layer by an airbone 10.6 um-hererodyne Doppler lidar

The retrieval of a two-dimensional (2D) wave-like structure in the atmospheric boundary layer by an airborne 10.6 μm-heterodyne Doppler lidar is investigated using numerical simulations. Two lidar sampling patterns of the atmosphere are considered here: a conical scan of the line-of-sight at 30° from nadir, and an along-track fore-aft 2D scan in a vertical plane. The lidar performance is discussed in terms of instrumental velocity error and representativity error. The retrieval of 2D wave-like structure is conducted for two different aircraft track orientations with respect to the organization of the 2D flow along track and cross track. The study shows that the representativity error is smaller for the analysis using the fore-aft 2D scan, than for the analysis using a conical scan (based on DABAS et al., 1997, variational analysis initialized with a sine fit as first guess), but the improvement in representativity error is obtained at the expense of the spatial coverage. In final, a combination of the two lidar scanning pattern seems to be the best solution to investigate 2D or 3D flow.