Assessment of helicopter brownout with a scanning lidar

There is very few quantitative data on Degraded Visual Environments (DVE) generated by the downwash of Rotary-Wing Platforms (RWP). In order to better understand the dynamics of DVE-RWP, we have used a scanning lidar to measure the cloud dimensions and optical depths generated by a helicopter hovering close to ground. It is shown that scanning lidar is a remarkable tool for quantifying DVE-RWP for low to moderate obscurations.