Under the radar

On the front line, a Royal Navy warship needs to be fast, agile and, most important of all, remain undetected by the enemy. So, how do you go about making a 500ft ship ‘invisible’?

Engineers at QinetiQ’s Funtington site are working alongside the MOD to ensure that their assets have all the necessary stealth capabilities to keep them off the radar. This is achieved through the use of antenna and radar cross-section measurements. The aim is to use testing and analysis to improve the radar signature of whole platforms, combat systems or individual items of equipment.

The team carries out work across the UK from Carlisle through to the Aberporth Range in Wales, where they have conducted radar cross-section assessments on the new Watchkeeper Unmanned Aerial Vehicle. The team has also been closely involved in the development of the Type 45 Destroyer through the completion of acceptance signature measurement trials. As a result, this warship has brought a new level of signal reduction to the Royal Navy fleet.

Around 90 per cent of the team’s work is carried out for the MOD but they also undertake commercial work in a range of markets, including the yachting industry. QinetiQ assisted the official investigation into the tragic incident involving the Pride of Bilbao ferry and the Ouzo yacht in 2006. Since then, the team has helped to raise awareness in the industry about the importance of having radar reflectors fitted to small vessels.
Wind turbines imageMore recently, the team has been involved in testing wind turbines that do not interfere with air surveillance radar signals. This is a great example of using military know-how spinning out into new areas.

Find out more about QinetiQ’s overall work in the area of stealth and smart technologies.

4 thoughts on “Under the radar

  1. I would like to know more about the radar reflectors and the masive safety aspect this has for the Marine and Aero industries, also an explanation on the wind turbines, I did not understand what you are trying to say, or add a link to give more details on both of these items

    • Steve,
      Wind turbines are large objects which reflect radar waves. They have a large ‘static’ radar cross section [RCS] (how big they appear to a radar) and a doppler RCs which is due to the moving blades. A radar, which looks for the doppler effect, will see the moving blades and an air traffic controller might not be able to confirm whether he has an undientified aircraft in his airspace and have to deal with the apparent safety issue. Turbines also cause a ‘shadow’ behind them into which the radar cannot see until the waves rejoin by natural bending. The way some radars work means that filters are set such that a certain level of reflected energy is processed out by the radar. If this level is set to remove a wind turbine, then higher level (altitude looking) beams may also filter out similar sized objects ie a 747!! This is down to the way the radar is used. If you add the large static RCS to the doppler RCS you add a [doppler] spike to the high static level and the total may swamp the radar filters thereby removing any useful information. Using stealth technology reduces the amount of energy going back to the radar and will alleviate some of the issues above so that normal air traffic or air defence radars can still do their job. This will reduce the very high levels of objections to planning permission for wind farms and, hence, increase the probability of the European and US Governments achieving their green energy targets. The RenewableUK website has a lot of info in their avaiation sections on this topic.
      That’s it in a bit of a nutshell, I hope it helps.

  2. I would like to see more about the small craft applications as I am an avid sailor. There have been times in the Baltic when I have been in fog and worried about the shipping around me.

  3. Thanks Steve, QinetiQ provides a UK sovereign capability in stealth materials across the three major signature control domains:
    Acoustic stealth, Radio frequency (RF) stealth & Electro-optic (EO) stealth materials.
    The wind turbines are thus coated with a stealth material so they are partially visible to maritime and air radar. You may ask why this is important, well if they are not coated they would impact the air and maritime traffic lanes and appear as objects on the radar.