HIGH-FREQUENCY BACKSCATTER FROM TERRAIN WITH TREES.

Abstract

At high frequency the ground may often be regarded as a plane mirror with negligible backscatter except at vertical incidence. At angles of incidence near grazing, any backscatter is due to objects on or above the ground, such as trees, provided the objects themselves have appreciable cross sections at high frequency. The standing-wave method of measuring radar cross sections was adapted for use at 26 Mc with targets on or above the ground, as described in a previous report. It was then further adapted for measuring cross sections at angles of elevation up to 22.5 deg, by raising the transmitting antenna with a balloon and moving the receiving probe along the transmitter-target line by means of ropes. Targets used were horizontal and vertical aluminum cylinders (using horizontal and vertical polarization, respectively, for the radiation) and an oak tree (using both polarizations). The results are relevant to ionospheric sounding by means of ground backscatter. (Author)

Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1966
Accession Number
AD0482575

Entities

People

  • J. G. Steele

Organizations

  • Stanford University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aluminum
  • Backscattering
  • Electromagnetic Radiation
  • Elevation
  • Frequency
  • Frequency Shift
  • Polarization
  • Radar Cross Sections
  • Radiation
  • Standing Waves
  • Transmitters
  • Transmitting
  • Waves

Fields of Study

  • Physics

Readers

  • Electrical Engineering
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering