Accession Number:

AD0755551

Title:

Open-Wire Transmission Lines Applied to the Measurement of the Macroscopic Electrical Properties of a Forest Region

Descriptive Note:

Special technical rept.

Corporate Author:

STANFORD RESEARCH INST MENLO PARK CA

Report Date:

1971-10-01

Pagination or Media Count:

131.0

Abstract:

The theoretical capabilities of two-conductor, open-wire transmission lines OWLs as probes to measure the macroscopic electrical properties of a forest are examined under the premise that a forest can be represented as a lossy dielectric slab. A laboratory experiment with a line inserted in a relatively homogeneous, isotropic slab of Styrofoam was performed to verify certain approximations in the analysis of such a line when a void hole exists in the slab near the line. The effective sensing radius for a 300-ohm line is shown to be about one and one-half line spacings. The limitations of a transmission-line probe for inhomogeneous and anisotropic dielectrics are discussed. The forest also is considered as a synthetic dielectric composed of lossy scatterers. The equivalent circuit of a short scatterer length small relative to the RF wavelength as a load on the transmission line is shown to be a lossy capacitor.

Subject Categories:

  • Radiofrequency Wave Propagation
  • Radio Communications

Distribution Statement:

APPROVED FOR PUBLIC RELEASE