Simulations of the retrieval of a two-dimensional wave-like structure in the atmospheric boundary layer by an airborne 10.6 mu m-heterodyne Doppler lidar

The retrieval of a two-dimensional (2D) wave-like structure in the atmosphe ric boundary layer by an airborne 10.6 mum-heterodyne Doppler lidar is inve stigated using numerical simulations. Two lidar sampling patterns of the at mosphere are considered here: a conical scan of the line-of-sight at 30 deg rees from nadir, and an along-track fore-aft 2D scan in a vertical plane. T he lidar performance is discussed in terms of instrumental velocity error a nd representativity error. The retrieval of 2D wave-like structure is condu cted for two different aircraft track orientations with respect to the orga nization of the 2D flow along track and cross track. The study shows that t he 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., 1 997, 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 patter n seems to be the best solution to investigate 2D or 3D flow.