Method and apparatus for making absolute range measurements

Patent · Tue Sep 24 04:00:00 EDT 2002

OSTI ID:874766

Earl, Dennis D ^[1]; Allison, Stephen W ^[1]; Cates, Michael R ^[2]; Sanders, Alvin J ^[1]

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1. Knoxville, TN
2. Oak Ridge, TN

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 a screen at least partially opaque at the wavelength. The screen has an aperture sized so as to produce a Fresnel diffraction pattern. A portion of the beam travels through the aperture to a detector spaced some distance from the screen. The detector detects the central intensity of the beam as well as a set of intensities displaced from a center of the aperture. The distance from the source to the target can then be calculated based upon the known wavelength, aperture radius, and beam intensity.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-00OR22725
• Assignee: UT Battelle, LLC (Oak Ridge, TN); The University of Tennessee Research Corporation (Knoxville, TN)
• Patent Number(s): 6,456,383
• Application Number: 09/705,847
• OSTI ID: 874766
• Country of Publication: United States
• Language: English

Related Subjects

/356/
absolute
aperture
apparatus
based
beam
calculated
center
central
detector
detects
diffraction
diffraction pattern
displaced
distance
distribution
electromagnetic
electromagnetic radiation
employs
fresnel
intensities
intensity
measurements
method
opaque
partially
pattern
portion
produce
radiation
radius
range
ranging
relates
screen
sends
set
sized
source
spaced
target
travels
wavelength