A new consortium called Aquila has won a 22 year contract to provide military air traffic control equipment for the UK armed forces. We consider what this means for wind farm developers.
Thousands of wind turbines cannot currently be built because of radar interference issues. The 28 Watchman Primary Surveillance Radar (PSR) installed at UK military airfields result in hundreds of radar planning objections every year.
The Ministry of Defence (MOD) contract is known as Project Marshall and was formerly known as Joint Military Air Traffic Services (JMATS). The two unsuccessful bidders were BAE Systems and Lockheed Martin.
Aquila is a consortium which was created specifically to bid for the MOD air traffic control system contract. The two main partners are NATS, the main UK civil air traffic control service, and Thales a French global aerospace company. There are two strategic subcontractors who are Jotron and Frequentis who provide radio and communications systems.
The company’s full name is Aquila Air Traffic Management Services Ltd, based in Basingstoke and the Managing Director is Justin Barratt.
Wind Turbine Tolerance Requirements
It is not known what requirements for wind turbine tolerance were made by the MOD, nor is it known what offers were made by the Aquila consortium. There do not appear to be any published statements regarding wind turbine tolerance.
Nevertheless by considering what is known regarding the structure of the contract and by considering what is known regarding Thales radar and Air Traffic Control systems it is possible to draw some limited conclusions.
|29 October 2014||Government announces award of contract to Aquila|
|1 April 2015||Aquila takes on current services and equipment|
|Within 2015||Aquila commences provision of upgraded air traffic control systems|
|Within 2021||All air traffic control systems upgraded or replaced|
|Within 2036||Aquila contract ends|
Wide Area Multilateration
The Aquila contract allows for the provision of Wide Area Multilateration (WAM) which is a relatively new air traffic control technology which can either augment or replace radar. NATS awarded Thales a WAM contract in 2010 for trial purposes in London Airports. It is a cooperative technology which means it can be an effective replacement for Secondary Surveillance Radar (SSR) but it is unlikely to be a direct replacement for PSR which are most affected by wind turbines.
Thales Primary Surveillance Radar
Thales standard PSR offering is the STAR 2000. This is an advanced digital radar that is already operational in the UK at a number of airports including Cardiff, Oxford, Belfast International and Inverness.
Importantly, a number of wind turbine radar trials were undertaken with the Thales radar at Manston Airport which has now closed. There are places where Thales STAR 2000 radar and wind turbines already coexist including Copenhagen and Bratislava.
The radar is an advanced digital radar that has some built-in capabilities which can be used to remove the effects of wind turbines. These can include:
- Non Auto Initiation Areas (NAIAs)
- Ground Vehicle Areas (GVAs)
Although the Thales STAR 2000 already has a degree of wind turbine tolerance new software is under development which promises to make the radar even more wind farm tolerant.
Thruput provides a digital filtering system that distinguishes primary radar returns from aircraft with those from known wind turbines. NATS may determine that combining Thruput with a STAR 2000 radar can be effective for mitigating wind turbine radar returns.
There are twenty eight military Watchman radar. It is possible that:
- Only some will be replaced
- The new radar signals will be combined
- Radar data from other sources (i.e. NATS existing radar) may be used
This could result in fewer radar objections because:
- Fewer radar will be impacted
- Combined radar pictures are more tolerant to wind turbine interference if only one radar is affected
- Blanking mitigation can be more effective because data is available from other unaffected radar sources
In-Fill Radar Integration
Integration of In-Fill radar from providers such as Aveillant, C-Speed and Terma should be more straight forward – especially where multiple MOD radar are currently likely to be impacted by a wind development.
Aquila implementation is scheduled between 2015 and 2021.
Implementation of Aquila could reduce the level of MOD Air Traffic Control (ATC) radar objections because:
- The new radar will generally be more wind turbine tolerant than the radar they replace.
- There are in-built mitigation capabilities
- There is the potential for add-on mitigation
- Radar networking means blanking mitigation should be more acceptable
- Some existing radar may not be replaced