DocumentCode :
1193638
Title :
Automated Precision Polarimeter for the HF-VHF Range
Author :
Green, T.C. ; Tarver, W.B.
Volume :
19
Issue :
4
fYear :
1970
Firstpage :
252
Lastpage :
259
Abstract :
An automated system for Stokes parameter-polarization analysis over the HF-VHF range is described. Axial ratio, orientation angle, polarization fraction, and polarization sense are determined by amplitude measurements using a conventional fieldintensity receiver. Six amplitude measurements from four crossed nonresonant dipoles, including quadrature sum and difference, eliminate the requirement for phase measurement. The antenna does not use active components and is adaptable for mobile or stationary operation. VSWR measurements on the antenna output cables show less than 1.2:1 (50 ohms) over the 2-70 MHz range. The antenna aperture increases from 1 × 10-5 square meters at 2.0 MHz to 0.019 square meters at 70 MHz. A solid-state sequencer processes each amplitude measurement separately through the receiver and digital conversion circuits (providing BCD output) to an incremental tape recorder. The Stokes parameter analysis is performed by an off-line digital computer using the magnetic tape data. This analysis permits computation of total received power from either set of orthogonal element measurements. When combined with the measured antenna aperture, power density (or field strength) also can be derived. Polarization fraction measurements for locally controlled signals show a mean of 1.02 as compared to a theoretical value of 1.00 (standard deviation of 0.1) over the 2-70 MHz range and polarization results consistent with propagation predictions.
Keywords :
Adaptive arrays; Antenna measurements; Aperture antennas; Dipole antennas; Magnetic analysis; Magnetic field measurement; Mobile antennas; Phase measurement; Polarization; Power measurement;
fLanguage :
English
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9456
Type :
jour
DOI :
10.1109/TIM.1970.4313909
Filename :
4313909
Link To Document :
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