Chinese Scientists Build Acoustic Lens for Underwater Drone Sonar

Researchers at Xiamen University developed an acoustic lens of concentric silicone rings with tungsten that corrects sound-wave distortion from an underwater drone's dome. In the lab the sonar beam narrowed from over 65° to 16–30°, and in the Jiulong River the lens cut reverberation by 11.98 dB and detected a sphere at about two meters.

• Lens of silicone rings with varying tungsten content flattens the sonar wavefront
• Beam width dropped from over 65° to 16–30° in lab tests
• In the Jiulong River reverberation fell 11.98 dB, making the object visible
• Next stage is testing in real seawater instead of artificial water