Deriving Lidar Sensor Requirements for Use in Wake Impact Alleviation Functions

Abstract

The paper complements previous works of the authors on lidar-based active wake impact alleviation control functions by investigating the lidar sensor requirements for such systems. This control system can increase the safety during wake vortex encounters by preventing a dangerous sudden (in particular rolling) motion, which often characterizes wake-vortex encounters. Such technology could provide an opportunity to relax the current wake-vortex-based separation minima and thus lead to a capacity gain for airports and in the terminal area. The performance of this system obviously strongly depends on the performance of the lidar sensor, however in a nontrivial way. The direct problem, i.e. determining the system performance obtained with a given sensor configuration, already requires setting up a fully coupled simulation environment. The inverse problem, i.e. determining the best suited set of sensor parameters, is approached in this work through parameter variations and sensitivity studies. Key performance parameters for assessing the overall system performance, and providing trends for sensor requirements are defined. As for most technical systems, the best configurations are characterized by a good tradeoff of the relevant parameters, in this case field of view, measurement range, spatial resolution, and measurement noise. The coupled simulations revealed that, contrary to the authors' expectations, very good results were already obtained with small ranges of 60 m and lateral fields of view of +/- 16°.