RADAR GROUND-CLUTTER SHIELDS
MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB
Pagination or Media Count:
Metal shields or fences are useful in reducing the ground clutter received by a radar. The design of a clutter shield for an L-band radar employing a 60-ft parabolic reflector with Cassegrainian geometry is verified by scale-model measurements at K sub a-band. It is shown that a 100-ft fence, at a distance 500ft from the radar, will give a nominal one-way clutter reduction of 20db. Tracking is expected to be virtually unaffected down to about 7.8 degrees in elevation, but the low limit on useful performance is about 4.8 degrees. More than 10-db additional clutter reduction is achieved by cutting rectangular slots in the top edge of the fence. However, these and other periodic structures are subject to resonances related to grating lobes. This phenomenon is investigated experimentally on the scale model and explained by a mathematical analysis utilizing the principle of stationary phase. A proposed nonperiodic edge treatment is expected to be free of this troublesome effect.
- Electrical and Electronic Equipment
- Active and Passive Radar Detection and Equipment