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. 02, 1985
Filed:
Jul. 26, 1982
Richard S Haendel, Iowa City, IA (US);
John C Wauer, Cedar Rapids, IA (US);
Rockwell International Corporation, El Segundo, CA (US);
Abstract
An FMCW distance measuring system is disclosed which provides a search and track function for enabling searching for nearer returns during altitude tracking, and for more accurately determining altitude rate. A portion of the transmitted wave in an FMCW altimeter is mixed with the received signal indicating distance to target to produce a beat frequency between the transmitted wave and the received wave. The transmitted wave is triangularly modulated to produce separate upsweep and downsweep modulations which are maintained to produce a constant beat frequency from the return signal. The up and downsweep of the triangular modulation are independently operable so that tracking may be maintained on either or both of the sweeps or one sweep may track while the other sweep is searching for a nearer return. By comparing the difference in the modulation slopes during the up and downsweep, a reading can be provided which is indicative of the rate of change in altitude. The operation thus allows altitude searching during nearest return tracking along with a combined instantaneous reading of altitude rate without additional circuitry.