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:
May. 12, 1987
Filed:
Jun. 13, 1985
Fritz Haberl, Munich, DE;
Abstract
A method and a circuit for processing the signals of an earth-horizon sen of a circularly orbiting earth satellite. The earth-horizon sensor operates in the infrared range and includes, in the focal plane of an input lens, a chopper disk which is periodically reciprocated with a determined chopper frequency (f) and has a diameter corresponding to the image of the earth, as well as a detector (1) receiving the periodically interrupted light radiation of oppositely located earth rims. The output signal of the detector (1) is demodulated synchronously with the chopper frequency (f) in order to derive an off-course signal. In order to suppress the influence of the earth anomaly, the amplified output signal of the detector (1) is additionally synchronously demodulated with the doubled chopper frequency (2f), according to the invention, in order to produce a symmetry signal.