Radar signature simulator based on Large Eddy Simulation of wake vortices in turbulent and stratified atmospheres
(2019)
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- Authors
- Supervisors
- Vanhoenacker-Janvier, Danielle
- Abstract
- A pair of counter-rotating vortices is created after roll-up of the wake of flying aircraft. Normally, wake vortices cannot be observed visually unless they capture some smoke, clouds, or aircraft contrails. Nevertheless, wake vortex turbulence is a serious hazard for the following aircraft especially during taking off and landing. The aircraft encountering a wake vortex system that has not dissipated enough, may be subjected to a strong rolling moment or to a strong downwash velocity causing a drop in lift. To prevent such a risk, safety separations between aircraft were imposed by ICAO at the beginning of the 70s. With the exponentially growing air traffic, those safety separations become too constraining for large and busy airports, limiting their capacity and flexibility, and causing many delays on departures and arrivals. In order to support the development of new systems, such as weather dependent separation, measurement tools are required, to provide in real time, information about the wake vortices intensity and their location relative to the glide path. The main sensors proposed are lidar and radar. They are complementary to detect wake vortices in all weather conditions: lidar is used in clear air and radar in rain. It is important to determine accurately the limitations of the radar detection and the parameters influencing them. This thesis provides a tool that allows the simulation of the wake vortices detection by radar in clear atmosphere and in the presence of rain. It can be used to optimize the radar parameters, to develop algorithms for the detection of wake vortices and to estimate their parameters. The novelty of the approach resides in the use of 3D fields from Large Eddy Simulations (LES) of the wake vortices in the turbulent stratified atmosphere, for the calculation of the radar backscattered signal. The LES output is used to simulate the time series and the Doppler spectra of the signal returning to the radar. The simulated signal is then analyzed to retrieve the position and the strength of the WVs. The platform developed and the models/methods tested, constitute a useful tool for the optimization of the radar configuration and parameters, and also for the improvement of the radar link budget. It could also be used, alongside with other algorithms, for a benchmark of methods for estimating the WVs strength. The radar simulator developed provides a useful tool for the optimization of the algorithms dedicated to the detection/classification of the WVs, using the backscattered radar signal.
- Affiliations
Citations
Kovalev, D. (2019). Radar signature simulator based on Large Eddy Simulation of wake vortices in turbulent and stratified atmospheres. https://hdl.handle.net/2078.5/171522