Detecting Microwave Emissions from Terrestrial Sources: A Feasibility Study

Abstract

A Dicke receiver has been designed and constructed in our effort to detect the 22 GHz spontaneous emission from water vapor. The receiver compares the brightness temperatures of two waveguides, one containing gaseous H20 at low pressure, the other containing dry air. Each waveguide is terminated with polished brass, which provides a low background brightness temperature, at one end and connects to the input of the receiver at the other end. The system is capable of detecting a brightness temperature difference of about 0.2 deg K. In this experiment, the radiation from water vapor produced the brightness temperature difference between source and reference of 0.28 to 0.33 deg K The experimental results proved that emission from water vapor was being detected.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1992
Accession Number
ADA248557

Entities

People

  • Thomas C. Ehlert
  • Thomas K. Ishii

Organizations

  • Marquette University

Tags

Communities of Interest

  • Counter IED
  • Human Systems
  • Materials and Manufacturing Processes

DTIC Thesaurus Topics

  • Absorption Coefficients
  • Amplifiers
  • Bandwidth
  • Cables
  • Coaxial Cables
  • Coefficients
  • Data Acquisition
  • Detection
  • Detectors
  • Digital Video
  • Frequency
  • Insertion Loss
  • Low Noise Amplifiers
  • Measurement
  • Radiation
  • Vapor Pressure
  • Water Vapor

Fields of Study

  • Physics

Readers

  • Atmospheric Remote Sensing.
  • Optical Physics and Photonics.
  • Thermal Physics or Thermal Science.