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Title: Noise pair velocity and range echo location system

Abstract

An echo-location method for microwaves, sound and light capable of using incoherent and arbitrary waveforms of wide bandwidth to measure velocity and range (and target size) simultaneously to high resolution. Two interferometers having very long and nearly equal delays are used in series with the target interposed. The delays can be longer than the target range of interest. The first interferometer imprints a partial coherence on an initially incoherent source which allows autocorrelation to be performed on the reflected signal to determine velocity. A coherent cross-correlation subsequent to the second interferometer with the source determines a velocity discriminated range. Dithering the second interferometer identifies portions of the cross-correlation belonging to a target apart from clutter moving at a different velocity. The velocity discrimination is insensitive to all slowly varying distortions in the signal path. Speckle in the image of target and antenna lobing due to parasitic reflections is minimal for an incoherent source. An arbitrary source which varies its spectrum dramatically and randomly from pulse to pulse creates a radar elusive to jamming. Monochromatic sources which jigger in frequency from pulse to pulse or combinations of monochromatic sources can simulate some benefits of incoherent broadband sources. Clutter which has amore » symmetrical velocity spectrum will self-cancel for short wavelengths, such as the apparent motion of ground surrounding target from a sidelooking airborne antenna.« less

Inventors:
 [1]
  1. (Oakland, CA)
Issue Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
OSTI Identifier:
872157
Patent Number(s):
5872628
Assignee:
Regents of University of California (Oakland, CA) LLNL
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
noise; pair; velocity; range; echo; location; echo-location; method; microwaves; sound; light; capable; incoherent; arbitrary; waveforms; wide; bandwidth; measure; target; size; simultaneously; resolution; interferometers; nearly; equal; delays; series; interposed; interferometer; imprints; partial; coherence; initially; source; allows; autocorrelation; performed; reflected; signal; determine; coherent; cross-correlation; subsequent; determines; discriminated; dithering; identifies; portions; belonging; apart; clutter; moving; discrimination; insensitive; slowly; varying; distortions; path; speckle; image; antenna; lobing; due; parasitic; reflections; minimal; varies; spectrum; dramatically; randomly; pulse; creates; radar; elusive; jamming; monochromatic; sources; jigger; frequency; combinations; simulate; benefits; broadband; symmetrical; self-cancel; wavelengths; apparent; motion; ground; surrounding; sidelooking; airborne; wide band; signal path; target size; reflected signal; nearly equal; measure velocity; wide bandwidth; incoherent source; coherent source; /356/

Citation Formats

Erskine, David J. Noise pair velocity and range echo location system. United States: N. p., 1999. Web.
Erskine, David J. Noise pair velocity and range echo location system. United States.
Erskine, David J. Fri . "Noise pair velocity and range echo location system". United States. https://www.osti.gov/servlets/purl/872157.
@article{osti_872157,
title = {Noise pair velocity and range echo location system},
author = {Erskine, David J.},
abstractNote = {An echo-location method for microwaves, sound and light capable of using incoherent and arbitrary waveforms of wide bandwidth to measure velocity and range (and target size) simultaneously to high resolution. Two interferometers having very long and nearly equal delays are used in series with the target interposed. The delays can be longer than the target range of interest. The first interferometer imprints a partial coherence on an initially incoherent source which allows autocorrelation to be performed on the reflected signal to determine velocity. A coherent cross-correlation subsequent to the second interferometer with the source determines a velocity discriminated range. Dithering the second interferometer identifies portions of the cross-correlation belonging to a target apart from clutter moving at a different velocity. The velocity discrimination is insensitive to all slowly varying distortions in the signal path. Speckle in the image of target and antenna lobing due to parasitic reflections is minimal for an incoherent source. An arbitrary source which varies its spectrum dramatically and randomly from pulse to pulse creates a radar elusive to jamming. Monochromatic sources which jigger in frequency from pulse to pulse or combinations of monochromatic sources can simulate some benefits of incoherent broadband sources. Clutter which has a symmetrical velocity spectrum will self-cancel for short wavelengths, such as the apparent motion of ground surrounding target from a sidelooking airborne antenna.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1999},
month = {1}
}

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