RADAR GROUND-CLUTTER SHIELDS

Abstract

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.

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Document Details

Document Type
Technical Report
Publication Date
Aug 19, 1965
Accession Number
AD0627465

Entities

People

  • D. A. Cahlander
  • F. I. Sheftman
  • J. Ruze

Organizations

  • Massachusetts Institute of Technology

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Angle Of Arrival
  • Angle Of Incidence
  • Detectors
  • Diffraction
  • Far Field
  • Frequency
  • Fresnel Zones
  • Geometry
  • Grazing Angles
  • Ground Clutter
  • Linear Polarization
  • Mathematical Analysis
  • Measurement
  • Near Field
  • Polarization
  • Reflectors
  • Test Facilities

Fields of Study

  • Physics

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Radar Systems Engineering.