The NRL Long-Wavelength Test Array

Abstract

The NRL Long-Wavelength Test Array (NLTA) was constructed to develop and test active baluns and electrically short dipoles for possible use as the primary wideband receiving elements for an emerging suite of large HF/VHF arrays including the Low Frequency Array (LOFAR) and the Long-Wavelength Array (LWA). Several dipoles of various designs and dimensions have been built and tested. Their useful range is when the dipoles arms are between approximately 1/8 and one wavelength long and the feedpoint is less that one half wavelength above ground. The NLTA, operating as an interferometer, has observed fringes from the brightest celestial sources in the frequency range from 10 to 50 MHz. The antenna temperatures vary from about 10% to 100% of the average brightness temperature of the Galactic background. With these parameters, it is relatively easy to make the amplifier noise levels low enough so that final system temperature is dominated by the Galactic background.

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Document Details

Document Type
Technical Report
Publication Date
Jun 22, 2007
Accession Number
ADA469880

Entities

People

  • Avi J. Cohen
  • B. C. Hicks
  • C. Gross
  • E. Polisensky
  • K. P. Stewart
  • K. W. Weiler
  • Namir Kassim
  • P. C. Crane
  • P. S. Ray

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Energy and Power Technologies
  • Sensors

DTIC Thesaurus Topics

  • Amplifiers
  • Astronomy
  • Circuit Boards
  • Coaxial Cables
  • Dipole Antennas
  • Flux Density
  • Frequency
  • Information Operations
  • Interferometers
  • Long Wavelengths
  • Measurement
  • Military Research
  • Radio Astronomy
  • Radio Frequency
  • Three Dimensional
  • Transmission Lines
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Astronomy/Astrophysics
  • Phased Array Antenna Design.