Hughes Electronics Corporation

Hughes Aircraft Company

University of New Mexico

Dean H Liskow

Joseph Nolan Paranto

Monica L Minden

Felix E Morgan

John P Blackburn

James P Kelly

Terry S Shirrod

A hand-held instrument (10) and associated method for providing optical measurements of the contour, range and motion of an object, such as a tympanic membrane of an ear, in real time, and to provide for simultaneous visualization of the object. The instrument (10) includes an illumination source (22) that projects an optical beam (24) through a grating (26) onto a gradient of refractive index lens (32) to project light and dark fringes onto the object at stepped phases determined by the grating position. Light reflected from the object is collected and focused onto an eye piece (18) to be observed by the operator. Simultaneously, reflected light from the object is focused onto a camera (46). The camera (46) generates an electrical signal in proportion to the light intensity received by the camera (46) to generate an image of the object. The image is then transmitted to processing systems to compute phase relationships in the reflected grating image to generate a contour map of the object. A drive system (28) is provided to move the grating (26) to different positions at a fraction of the spatial period of the grating during a measurement to provide phase sensitivity, eliminate reflectivity variations and reduce background noise.

Moire topographic measurement

A miniature grating drive device (216) for accurately and precisely positioning a grating (236) of a projection Moire topography measurement system where the Moire topography measurement system is included as part of a hand-held medical instrument for providing surface measurements of inaccessible living membranes. The drive device (216) includes two separate piezoelectric bimorph actuators (248, 256) for positioning the grating (236) at three precise locations. The first piezoelectric bimorph actuator (256) accurately positions the grating (236) at a first location, and the second piezoelectric bimorph (248) actuator accurately positions a base (232) on which the first piezoelectric actuator (256) is attached to move the grating (236) to a second location.

Miniature grating device

An laser radar system employing transmitted random and pseudo random optical pulse trains and signal processing that provides unambiguous range and Doppler velocity data. The system comprises a diode-pumped fiber laser local oscillator and an optical random pulse signal generator comprising a mode-locked fiber laser source for generating and transmitted randomly spaced optical pulses. A heterodyne output pulse monitor processes the local oscillator signals and samples the transmitted optical pulses. A heterodyne receiver detector processes the local oscillator signals and received optical pulses reflected from a target. An acoustic charge transport delay line provides a selectable signal delay for the signal provided by the heterodyne optical pulse monitor, and a mixer mixes signals provided by the heterodyne receiver detector and delay line and provides correlation output signals. A Doppler analyzer processes the correlation output signals from the mixer to provide frequency spectrum for each range bin, and an executive processor processes the frequency spectra from the Doppler analyzer to provide a range-resolved Doppler image on the display. The range-resolved Doppler output signals provided by the executive processor allow identification of a wideband weather signature and a narrow band target signature that are displayed on the display. The system employs a single waveform to provide the needed measurements, and eliminates trade-offs between range and velocity ambiguities. The present invention may be employed in vehicular collision avoidance radars and laser sensors, and in adaptive cruise control, robotic vision, and metrology-gauging applications.

Random pulse burst range-resolved doppler laser radar

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Albuquerque, NM, United States of America

Dean H Liskow