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:
Nov. 10, 1998
Filed:
Oct. 07, 1996
Steven V Czarnecki, Apalachin, NY (US);
James A Johnson, Newark Valley, NY (US);
Clifford M Gray, Owego, NY (US);
George A VerWys, Vestal, NY (US);
Carl Gerst, Skaneateles, NY (US);
Lockheed Martin Corporation, Bethesda, MD (US);
Abstract
In a long base line interferometer system for determining the position of a transmitter, the phase differences between the signal received by the antennas at each end of the base line are monitored as the interferometer moves through a measurement path to obtain phase difference measurements distributed along the measurement path. A cost function involving measuring the sum of the squares of the differences between measured values and predicted values is determined for each of a set of trial location grid points and the grid point with the lowest cost function is selected as a starting point for determining the transmitter location by least squares convergence. In evaluating the cost function, the predicted values are obtained from the equation: ##EQU1## in which .o slashed..sub.0 is unknown phase offset and the X and Y coordinates of the transmitter are unknown. The least squares convergence is carried out by iteratively adding corrections to predicted values for the unknowns until convergence occurs.