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:
Jan. 19, 1999
Filed:
Sep. 18, 1996
Hunt W Small, Saratoga, CA (US);
John E Bergesen, San Bruno, CA (US);
Brian J Howley, Mountain View, CA (US);
Lockheed Martin Corp., Sunnyvale, CA (US);
Abstract
Real time correction to ground generated satellite ephemeris implements a reference trajectory management module (334), an error estimation module (336), an parameter calculation module (338) and a position information management module (340). The reference trajectory management module (334) accesses reference trajectory data such as ground generated ephemeris data which is uplinked to a spacecraft through a communications unit (312). The position information management module (340) accesses and interprets position information such as Global Positioning System (GPS) measurement data to provide measured spacecraft positions. The parameter calculation module (338) calculates spacecraft position and velocity from the reference trajectory data. The error estimation module (336) compares the measured and calculated positions to provide a position difference, smoothes the position difference to filter anomalous data, and provides a correction term for the determination of corrected spacecraft orbital parameters such as position and velocity. The time rate of change of the correction term may be used to provide additional correction to the orbital parameters.