Suppression of Radar Clutter from Wind Turbines

At a Glance

Researchers at Colorado State University have developed a system to identify and filter unwanted wind turbine radar signatures. The technique uses prior observations as the signal model to suppress the wind turbine signature. It has been successfully applied to active turbine fields, significantly reducing the bias in the spectral moment estimates for reflectivity, radial mean Doppler velocity, and spectrum width.

Background

The installed wind power in the U.S. and abroad has experienced tremendous growth in recent years and wind farms are becoming an increasingly common sight. Unfortunately, wind turbines are dynamic radar scatterers that interfere with all bands of radio waves, whether for weather, air-surveillance, or defense. When turbines are observed in the same radar volume as other objects, the echoes from the turbine can mask the target of interest. Because it is time-varying and often very complex (particularly for larger wind farms), the wind turbine’s radar signature is difficult to suppress. This is challenging for many applications, as the signature has characteristics similar to weather and aircraft.

Overview

This innovation presents a simple method for reliably mitigating the wind turbine signature in radar observations. Whereas previous approaches have considered the wind turbine as a non-cooperative target, this innovation utilizes state information provided by the turbine itself to predict the radar signature. With just a few key parameters from the turbine, including rotation angle, yaw angle, and rotation rate, a characteristic radar signature for the turbine can be determined and removed from the radar observation.

By removing or suppressing the echo contributed by the wind turbine, the desired targets can be more effectively detected and relevant target parameters can be more accurately estimated. The innovation can be implemented in an operational environment with minimal processing delay and is effective for a single turbine or a multitude of turbines within the radar’s domain.

This innovation is very general and may be applied to any type of wind turbine, including three-blade, two-blade, and vertical axis wind turbines. The radar may be stationary or in motion (e.g., airplane or drone mounted radars, land-based vehicles or any other mobile unit). Although designed with wind turbines in mind, this innovation may be applied to any other cyclostationary process that introduces unwanted radar clutter.

Benefits

  • Simple method for determining and suppressing radar clutter from wind turbines.
  • Utilizes turbine state information and look-up tables or basic models to estimate turbine radar signature.
  • Suitable for single or multiple turbines, stationary or mobile radars.
  • Applicable to any type of radar, including weather, air-surveillance, and synthetic aperture radar.

Applications

  • Weather forecasting
  • Air traffic control
  • Defense
Last Updated: April 2024
Drawing explaining wind turbine interference
Opportunity

Available for Licensing
TRL: 7

IP Status
Inventors

Robert M Beauchamp
V. Chandrasekar

Reference Number
17-004
Licensing Manager

Aly Hoeher
Aly.Hoeher@colostate.edu
970.491.4077