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Title: Method and apparatus for reducing range ambiguity in synthetic aperture radar

Abstract

A modified Synthetic Aperture Radar (SAR) system with reduced sensitivity to range ambiguities, and which uses secondary receiver channels to detect the range ambiguous signals and subtract them from the signal received by the main channel. Both desired and range ambiguous signals are detected by a main receiver and by one or more identical secondary receivers. All receivers are connected to a common antenna with two or more feed systems offset in elevation (e.g., a reflector antenna with multiple feed horns or a phased array with multiple phase shift networks. The secondary receiver output(s) is (are) then subtracted from the main receiver output in such a way as to cancel the ambiguous signals while only slightly attenuating the desired signal and slightly increasing the noise in the main channel, and thus does not significantly affect the desired signal. This subtraction may be done in real time, or the outputs of the receivers may be recorded separately and combined during signal processing.

Inventors:
 [1]
  1. San Ramon, CA
Issue Date:
Research Org.:
Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
OSTI Identifier:
872614
Patent Number(s):
5973634
Application Number:
08/988604
Assignee:
Regents of University of California (Oakland, CA)
Patent Classifications (CPCs):
G - PHYSICS G01 - MEASURING G01S - RADIO DIRECTION-FINDING
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; apparatus; reducing; range; ambiguity; synthetic; aperture; radar; modified; reduced; sensitivity; ambiguities; secondary; receiver; channels; detect; ambiguous; signals; subtract; signal; received; main; channel; desired; detected; identical; receivers; connected; common; antenna; feed; systems; offset; elevation; reflector; multiple; horns; phased; array; phase; shift; networks; output; subtracted; cancel; slightly; attenuating; increasing; noise; significantly; affect; subtraction; time; outputs; recorded; separately; combined; processing; aperture radar; signal processing; phase shift; main channel; synthetic aperture; reduced sensitivity; signal received; signal process; phased array; multiple feed; multiple phase; significantly affect; /342/

Citation Formats

Kare, Jordin T. Method and apparatus for reducing range ambiguity in synthetic aperture radar. United States: N. p., 1999. Web.
Kare, Jordin T. Method and apparatus for reducing range ambiguity in synthetic aperture radar. United States.
Kare, Jordin T. Tue . "Method and apparatus for reducing range ambiguity in synthetic aperture radar". United States. https://www.osti.gov/servlets/purl/872614.
@article{osti_872614,
title = {Method and apparatus for reducing range ambiguity in synthetic aperture radar},
author = {Kare, Jordin T},
abstractNote = {A modified Synthetic Aperture Radar (SAR) system with reduced sensitivity to range ambiguities, and which uses secondary receiver channels to detect the range ambiguous signals and subtract them from the signal received by the main channel. Both desired and range ambiguous signals are detected by a main receiver and by one or more identical secondary receivers. All receivers are connected to a common antenna with two or more feed systems offset in elevation (e.g., a reflector antenna with multiple feed horns or a phased array with multiple phase shift networks. The secondary receiver output(s) is (are) then subtracted from the main receiver output in such a way as to cancel the ambiguous signals while only slightly attenuating the desired signal and slightly increasing the noise in the main channel, and thus does not significantly affect the desired signal. This subtraction may be done in real time, or the outputs of the receivers may be recorded separately and combined during signal processing.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Oct 26 00:00:00 EDT 1999},
month = {Tue Oct 26 00:00:00 EDT 1999}
}