Research/Patents/US 4641143
US 4641143

TWO-DIMENSIONAL ACQUISITION SYSTEM USING CIRCULAR ARRAY

Assignee

SANDERS ASSOCIATES, INC., A DE CORP.

Filed

Sep 28, 1983

Granted

Feb 3, 1987

Location

MERRIMACK NH US

Abstract

A frequency-and-direction-finding system (10) employing a circular array (12) performs a two-dimensional Fourier transformation in space and time on the signals from the individual elements. The results of the transformation are fed to multipliers (22) that multiply them by correction factors that are derived from antenna patterns of the array but do not include the bearing-dependent factors in those systems. The result is an ensemble of values whose relative phases represent a spatial frequency proportional to the bearing angle of the source. Accordingly, a second fast-Fourier-transform circuit (26) operating on this ensemble of values produces an output only on an output port corresponding to the bearing angle of the source.

Source: Google Patents

35 USC §181 Secrecy Order

Imposed

Apr 9, 1985

Rescinded

Mar 28, 1986

Duration

11 months

Inventor

  • 1JOHN T. APOSTOLOS

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Back to patent indexSource: USPTO 35 USC §181 secrecy order records