The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 26, 2006
Filed:
Aug. 20, 2004
Brett A. Williams, Arlington, TX (US);
Mark A. Turner, Arlington, TX (US);
Brian C. Baker, Arlington, TX (US);
Brett A. Williams, Arlington, TX (US);
Mark A. Turner, Arlington, TX (US);
Brian C. Baker, Arlington, TX (US);
Lockheed Martin Corporation, Bethesda, MD (US);
Abstract
A method and apparatus for finding a relative direction to, a radial speed of, and a distance to a target is described. A laser source illuminates the target and the Doppler shifted return beam is incident upon a window system at an angle and is transmitted therethrough. The magnitude of the transmitted Doppler shifted beam decreases due to Fresnel transmittance. Opposing photomixers then detect this transmitted Doppler shifted beam, thereby creating a pair of detection signals that are mixed with a local oscillator signal. The mixing process creates Doppler frequency signals that are subsequently processed to determine the radial speed of the target. Due to the Doppler frequency component of the signals, objects in the same direction, but moving at different radial speeds, can be discriminated, as the relative direction processing occurs after the Doppler processing.