Non-destructive test system inspects radar domes

A non-destructive Terahertz inspection system has been developed at the Fraunhofer Institute for Physical Measurement Techniques IPM (Kaiserslautern, Germany) to identify imperfections in the radar domes of aircraft during production.

Aircraft radar domes are made of fiberglass composites. But if imperfections such as foreign particles, drops of water or air bubbles in the fiberglass resin arise during production, over time they can cause fine cracks through which moisture can seep. This causes interference in radio traffic through the aircraft nose, introducing static into the signal.

The main challenge facing the researchers was to determine which Terahertz frequencies would have to be used to bombard the material to achieve the most effective results for the various imperfections. Higher frequencies create better resolution, while lower frequencies have less difficulty penetrating the material. To solve the problem, the system allows the researchers to select from a range of different frequencies depending on the defects they are looking for.

The scientists have already developed a prototype of the system. It will be presented at the Control trade fair in Stuttgart, Germany between May 8-11 in Hall 1 on stand 1502. Around a year from now, the researchers plan to have refined the system so that it will be able to scan and analyze the noses of aircraft automatically.

-- by Dave Wilson, Senior Editor, Vision Systems Design