How it works – Aveillant 3D Holographic Radar

Wind turbines interfere with airport and military radar systems so various companies are trying to fix the problem. There are at least 50 mitigation solutions that have reared their head at some point in the past ten years.

Mitigation

The most common forms of mitigation which are considered are: Radar blanking; Radar upgrade; Wind farm design and Radar In-Fill. Radar In-Fill solutions work by replacing data from the affected radar with data from an unaffected radar. In some cases the unaffected radar is a conventional radar that won’t see the turbines or it can be a radar that won’t be affected by the turbine.

There are a number of radar mitigation solutions that can be considered for wind farms including:

• Aveillant 3D Holographic Radar™
• C Speed LightWave radar
• Raytheon/NATS Project RM
• Terma Scanter 4002
• Cyrrus Smartener
• Thruput MIDAS II
• Thales STAR 2000

Aveillant

Aveillant’s 3D Holographic Radar is an in-fill radar that is designed not to be affected by wind turbines. In this article we will consider:

• Practical issues associated with implementing Aveillant mitigation
• How the Aveillant 3D Holographic Radar differs from a conventional radar
• How the radar performed in US military trials designed to compare wind turbine mitigation radar

Radar Siting

Conventional radar are typically installed at airports or on the tops of hills that have a good 360 degree view of the sky. The cheapest form of the Aveillant solution has limited range (compared to more expensive versions) and 90 degrees of coverage meaning that it is best located just beyond a wind farm’s boundary to give optimal coverage around the wind farm.

The new radar will need robust and secure siting, electricity supply and data communications services to ensure its integrity matches that of the radar system being mitigated.

Conventional 2D Vs Aveillant 3D

The main differences between an Aveillant 3D radar and a conventional 2D radar (e.g. cSpeed and Terma) are shown in the table below:

US Trial

In July 2014 the US government publicised the results [1] of government trials comparing the performance of various wind farm mitigation technologies.

It published graphs comparing the technologies for flights above wind farms and also flights away from wind farms.

The two specific measures related to detection of genuine aircraft as well as the likelihood of displaying false returns. An inspection of the published results suggests that the Aveillant sensor is the best performer (not quite perfect) both in the presence and absence of wind turbines.

Sensor Performance

Aveillant publishes the following technical data:

Summary

The main disadvantages are the potential requirement to host radar equipment on a new site and the fact that the system has no operational track record.  Key advantages of the Aveillant solution are ease of integration and the excellent technical performance demonstrated in the US Government trials.

Sources

[1] “Summary of Test Results for the Interagency Field Test &Evaluation of Wind Turbine – Radar Interference Mitigation Technologies PUBLIC RELEASE” by U.S. Department of Defense, U.S. Department of Homeland Security, Federal Aviation Administration and U.S. Department of Energy. Publicly published July 9^th 2014. Last Accessed 23/12/2014.