Physics:Clutter fence

The Nike Zeus target tracking radars used a complex clutter fence to block signals reflecting off nearby buildings and other radars.

The clutter fences for the Sea Wolf trackers can be seen on top of the hangar and bridge of this Type 23 Frigate

A clutter fence is a device used with some radar systems to prevent reflections from nearby objects reaching the receiver. They are normally constructed out of conventional metal fencing material. They may serve a secondary role in protecting crews on the ground from the microwave signal of some very high-powered radars.

References

• Smith Phillip Hagar, "Clutter fence for suppression of electromagnetic energy", US patent Grant US3683394, published 8 August 1972, assigned to Bell Telephone