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:
Jul. 01, 1980
Filed:
Feb. 21, 1978
Atul Jain, Altadena, CA (US);
Other;
Abstract
Apparatus for detecting relative motion between a rough reflecting surface and a wave transmitting and receiving system in a plane parallel or perpendicular to the reflecting surface comprised of a transmitter (radar, laser, acoustic, and the like), a receiver having the same or different aperture as the transmitter, and means for detecting the finest interference fringes in the reflected wave pattern. Each fringe detected represents relative motion through a distance, S, that is a function of the maximum dimension, D, of the transmitting aperture. By counting fringes, total relative motion is determined, and by counting fringes for a unit of time, the rate of that motion is determined. For a small transmitting aperture, the distance, S, between fringes is directly related to kD in the parallel plane and to kD/tan .theta., in the normal plane, where .theta. is the angle between a reference axis normal to the reflecting surface and the axis of the receiving aperture, and k is a calibration constant equal to unity when the transmitting and receiving apertures are at the same distance, H, from the reflecting surface. For a large aperture, S.perspectiveto..lambda.H/kD in the parallel plane and S.perspectiveto..lambda.H/kD tan .theta. in the normal plane. In either plane, for the condition of k.perspectiveto.1, the spacing S.perspectiveto..lambda.H/D and S.perspectiveto..lambda.H/D tan .theta. can be measured with a linear scan array so that with .lambda., D and .theta. known, the distance H can be determined.