Radar detection of wake vortex behind the aircraft: the detection range problem

TL;DR

This paper demonstrates the detection of aircraft wake vortices at distances over 10 km using X-band radar, analyzing signal characteristics and challenges in stable detection.

Contribution

It presents the first successful long-range radar detection of wake vortices and analyzes their radar signatures and detection challenges.

Findings

Wake vortices extend up to 6 km behind aircraft.

Vortex scattering power is about 10 dB lower than the aircraft.

Doppler Signal-to-Clutter Ratio remains relatively high.

Abstract

In this study, we showcased the detection of the wake vortex produced by a medium aircraft at distances exceeding 10 km using an X-band pulse-Doppler radar. We analyzed radar signals within the range profiles behind a Boeing 737 aircraft on February 7, 2021, within the airspace of the Runway Protection Zone (RPZ) at Tianhe Airport, Wuhan, China. The findings revealed that the wake vortex extended up to 6 km from the aircraft, which is 10 km from the radar, displaying distinct stages characterized by scattering patterns and Doppler signatures. Despite the wake vortex exhibiting a scattering power approximately 10 dB lower than that of the aircraft, its Doppler Signal-to-Clutter Ratio (DSCR) values were only 5 dB lower, indicating a notably strong scattering power within a single radar bin. Additionally, certain radar parameters proved inconsistent in the stable detection and tracking of wake vortex, aligning with our earlier concept of cognitive micro-Doppler radar.