Sri International

Gas Research Institute

Jan E Van Der Laan

Ronald E Pelrine

Robert L Byer

David E Cooper

David A Watt

David S Stoker

John Brian Burns

Jesse Wodin

Cregg Cowan

Eric Lavelle

Motilal Agrawal

Sylvie Carlisle

Russell E Warren

Sunil Goda

Arne Rosengreen

Edward R Murray

Example gravity gradiometers are described that utilize high precision resonant optical cavities to measure changes in gravitational forces at high sensitivities. In one example, a sensing system includes a gravity gradiometer and a controller. The gravity gradiometer includes a first mirror and a second mirror arranged to form an optical cavity having an optical axis. The controller is configured to detect, responsive to displacement of at least one of the first mirror and the second mirror along the optical axis, a change in gravity gradient.

Compact and highly sensitive gravity gradiometer

The present invention relates to a method and apparatus for long-range facial and ocular acquisition. One embodiment of a system for acquiring an image of a subject's facial feature(s) includes a steerable telescope configured to acquire the image of the facial feature(s), a first computational imaging element configured to minimize the effect of defocus in the image of the facial feature(s), and a second computational imaging element configured to minimize the effects of motion blur. In one embodiment, the detecting, the acquiring, the minimizing the effect of the motion, and the minimizing the effect of the defocus are performed automatically without a human input.

Method and apparatus for automatically acquiring facial, ocular, and iris images from moving subjects at long-range

This specification discloses a method and apparatus for the mobile and remote detection of a gas, such as methane, in the atmosphere. The apparatus includes a TDL based Light Detection and Ranging (LIDAR) driven at carrier frequency lying within the absorption line of the gas. The apparatus also drives the TDL with a modulation frequency to generate upper and lower sidebands in the output of the TDL and with a low ramp frequency to sweep the output of the TDL across twice the width of the pressure-broadened absorption line of the gas, preferably the first overtone absorption line in the case of methane detection. The apparatus include reference and calibration cells or chambers, and includes a light collector and detectors to detect the quantity and modulation of the light that passes the reference or calibration cells and that is received by the apparatus after reflection back toward the apparatus from an uncooperative target. The apparatus further includes a signal processor that applies a derivative spectroscopy technique, such as frequency modulation spectroscopy or wavelength modulation spectroscopy, to determine the presence of the gas in the atmosphere.

Apparatus and method of remote gas trace detection

Gases in the atmosphere are detected remotely using a frequency-mixed CO.sub.2 laser beam formed by passing the beam from a first CO.sub.2 laser through a frequency doubler and then frequency-adding the output to the frequency from a second CO.sub.2 laser to obtain wavelengths in the 3 micron region. A first wavelength in this region, preselected for nonabsorption by the gases to be detected, is transmitted through the gases toward an object capable of reflecting the beam back. A second wavelength preselected as highly absorbed by the gases to be detected is then transmitted. The presence and quantity of the gases is then determined by the difference in the amount respectively absorbed at the two wavelengths.

Frequency-mixed CO.sub.2 laser radar for remote detection of gases in

Growing community of inventors

Palo Alto, CA, United States of America

Jan E Van Der Laan