Patent Number: 7,132,981

Title: Method of locating object using phase differences among multiple frequency beacons transmitted from spaced apart transmitter sites

Abstract: A technique for geolocating (mobile) objects within an environment where other locating systems, such as GPS-based systems, may not be expected to operate successfully, uses at least three transmitter sites whose geolocations are fixed and known, and which transmit dual frequency beacons that are readily received by a mobile receiver within the environment of interest. The object's receiver processes the three sets of received signals by measuring the phase differences among respective pairs of the beacons, and then processes these phase differences to perform time difference of arrival-based or time of arrival-based distance information to locate the object relative to the beacons sites. Phase errors or offsets are readily calibrated out, to realize geolocation information at the mobile receiver.

Inventors: Roberts; Richard D. (West Melbourne, FL)

Assignee: Harris Corporation

International Classification: G01S 5/06 (20060101)

Expiration Date: 2019-11-07 0:00:00