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Title: Method and apparatus for making absolute range measurements

Abstract

This invention relates to a method and apparatus for making absolute distance or ranging measurements using Fresnel diffraction. The invention employs a source of electromagnetic radiation having a known wavelength or wavelength distribution, which sends a beam of electromagnetic radiation through an object which causes it to be split (hereinafter referred to as a beam splitter''), and then to a target. The beam is reflected from the target onto a screen containing an aperture spaced a known distance from the beam splitter. The aperture is sized so as to produce a Fresnel diffraction pattern. A portion of the beam travels through the aperture to a detector, spaced a known distance from the screen. The detector detects the central intensity of the beam. The distance from the object which causes the beam to be split to the target can then be calculated based upon the known wavelength, aperture radius, beam intensity, and distance from the detector to the screen. Several apparatus embodiments are disclosed for practicing the method embodiments of the present invention. 9 figs.

Inventors:
; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE; USDOE, Washington, DC (United States)
OSTI Identifier:
6158742
Patent Number(s):
US 5914785; A
Application Number:
PPN: US 9-018502
Assignee:
Univ. of Tennessee Research Corp., Knoxville, TN (United States); Lockheed Martin Energy Research Corp., Oak Ridge, TN (United States) PTO; EDB-99-081368
DOE Contract Number:  
AC05-96OR22464
Resource Type:
Patent
Resource Relation:
Patent File Date: 4 Feb 1998
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION; BEAM SPLITTING; DESIGN; MEASURING METHODS; OPTICAL SYSTEMS; RANGE FINDERS; MEASURING INSTRUMENTS; 440800* - Miscellaneous Instrumentation- (1990-)

Citation Formats

Allison, S.W., Cates, M.R., Key, W.S., Sanders, A.J., and Earl, D.D. Method and apparatus for making absolute range measurements. United States: N. p., 1999. Web.
Allison, S.W., Cates, M.R., Key, W.S., Sanders, A.J., & Earl, D.D. Method and apparatus for making absolute range measurements. United States.
Allison, S.W., Cates, M.R., Key, W.S., Sanders, A.J., and Earl, D.D. Tue . "Method and apparatus for making absolute range measurements". United States.
@article{osti_6158742,
title = {Method and apparatus for making absolute range measurements},
author = {Allison, S.W. and Cates, M.R. and Key, W.S. and Sanders, A.J. and Earl, D.D.},
abstractNote = {This invention relates to a method and apparatus for making absolute distance or ranging measurements using Fresnel diffraction. The invention employs a source of electromagnetic radiation having a known wavelength or wavelength distribution, which sends a beam of electromagnetic radiation through an object which causes it to be split (hereinafter referred to as a beam splitter''), and then to a target. The beam is reflected from the target onto a screen containing an aperture spaced a known distance from the beam splitter. The aperture is sized so as to produce a Fresnel diffraction pattern. A portion of the beam travels through the aperture to a detector, spaced a known distance from the screen. The detector detects the central intensity of the beam. The distance from the object which causes the beam to be split to the target can then be calculated based upon the known wavelength, aperture radius, beam intensity, and distance from the detector to the screen. Several apparatus embodiments are disclosed for practicing the method embodiments of the present invention. 9 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Jun 22 00:00:00 EDT 1999},
month = {Tue Jun 22 00:00:00 EDT 1999}
}