Accession Number:

ADA012858

Title:

Photography at Radiowavelengths.

Descriptive Note:

Final rept. Jun 71-Sep 74,

Corporate Author:

ALASKA UNIV COLLEGE GEOPHYSICAL INST

Personal Author(s):

Report Date:

1975-03-01

Pagination or Media Count:

62.0

Abstract:

The report contains the description of the concept and the instrumentation developed for imaging radiowave object fields. The electromagnetic field in the plane of an antenna array is specified by the waves arriving from different directions. The complex electromagnetic field may be sampled by the antennas in the array, faithfully amplified through those many identical receivers, to energize an equivalent array of ultrasonic emitters. The Fraunhofer image formed by the ultrasonic array may then be converted to yield a visible image. The imaging system developed is a one-dimensional version. It consists of a row of 20 antennas equiangular spirals, 20 identical, high gain receivers and a linear array of ultrasonic emitters. The one-dimensional ultrasonic image is then detected by an array of pinducers, amplified and made to proportionately illuminate a row of L.E.D. light bulbs. The L.E.D. row is then photographed by means of a continuous run, 16 mm camera.

Subject Categories:

  • Atmospheric Physics
  • Recording and Playback Devices

Distribution Statement:

APPROVED FOR PUBLIC RELEASE