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. 05, 2000
Filed:
Dec. 30, 1996
Milford Pike Castles, San Antonio, TX (US);
Austin Walker Boyd, Jr, Fredericksburg, VA (US);
James Andrew Moryl, San Antonio, TX (US);
Southwest Research Institute, San Antonio, TX (US);
Abstract
A method for determining the geolocation of an object such as a vehicle traversing the earth's surface or airborne thereabove includes employing a device which is capable of operating autonomously to transmit signals to a selected low earth orbit (LEO) satellite for relay to a receiving station whose position is known, identifying the device and its geolocation, speed, altitude and/or heading. The device includes a microcomputer which operates a Global Positioning System (GPS) receiver for receiving GPS signals to identify the device geolocation and the precise time. A nonvolatile memory on board the device stores LEO satellite ephemeris data, satellite operational and message formatting parameters, LEO satellite visibility footprint data and visibility contour information for the device caused by obstacles which are permanently or temporarily in proximity to the device during deployment and which block transmission of signals between the device and the LEO satellite, depending on relative positions. Geolocation information is transmitted to a LEO satellite for relay to the receiving station after calculation of covisibility of the satellite with the receiving station and the transmitter antenna for the device, taking into account the device visibility contour and heading. The device transmitter antenna may have a steering mechanism for causing the antenna to be aimed at a predetermined azimuth and elevation wherein the transmitted signals will be intercepted by the LEO satellite.