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:
Apr. 28, 1992
Filed:
Jul. 31, 1991
Albert J Berni, Houston, TX (US);
Shell Oil Company, Houston, TX (US);
Abstract
Methods and apparatus are provided for remotely sensing motions of the earth from the Doppler shift of reflected electromagnetic waves. The apparatus is based on a heterodyne continuous wave or pulsed laser system. The airborne laser system described herein is intended to remotely sense seismic motion. Motion of the earth's surface, when coupled to a reflector, causes a continuously shifting frequency (Doppler) of the reflected sensing laser beam, the Doppler frequency being proportional to the particle velocity of the ground. The method uses electromagnetic waves reflected from reflectors, some of which are coupled to the earth's surface. Similarly, 'inertial' reflective surfaces (i.e., vibrationally isolated from any earth motions) are also located at the surface of the earth and employed by the apparatus and methods of the present invention. Both an inertial reflector and an earth-coupled reflector are positioned at each location for which seismic signals are desired.