Electromagnetic location and display system and method
First Claim
1. A method for determining a likely region for an object comprising:
- generating a set of calibration maps for an area by the steps of;
transmitting a plurality of signals from a plurality of known transmitter locations;
receiving said plurality of signals and measuring a difference between two properties for each of said signals of said plurality of signals, said receiving being from known receiver locations; and
recording a plurality of calibration maps, each said calibration map relating one of said differences between two properties for each of said signals of said plurality of signals to corresponding locations within said area;
transmitting a location signal;
receiving said location signal and measuring a difference between two properties for said location signal;
comparing said difference between two properties for said location signal with a corresponding said calibration map to generate a plurality of comparison maps;
combining said plurality of said comparison maps to generate a combination map; and
determining said likely region, said likely region being a region within said combination map defined by a predetermined threshold.
2 Assignments
0 Petitions
Accused Products
Abstract
An unknown location for a transmitter/receiver is determined using a calibration process. An area is established with reference receivers at known locations and a mobile transmitter provides a location signal. An alternative embodiment uses reference transmitters and a mobile receiver. For calibration, the transmitter is placed at multiple measured locations and signal measurements are taken to generate a calibration map. Multiple signal measurements may be taken at each receiver, and multiple receivers may be used. In one embodiment, signal measurements include a near-field phase. In operation, one or more location signals are measured at one or more receivers. The measured signals are compared with the calibration maps to generate a set of comparison maps which are combined to generate a likelihood map. A likely region and most likely location are determined from the likelihood map and may be displayed relative to a map of the environment.
52 Citations
16 Claims
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1. A method for determining a likely region for an object comprising:
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generating a set of calibration maps for an area by the steps of; transmitting a plurality of signals from a plurality of known transmitter locations; receiving said plurality of signals and measuring a difference between two properties for each of said signals of said plurality of signals, said receiving being from known receiver locations; and recording a plurality of calibration maps, each said calibration map relating one of said differences between two properties for each of said signals of said plurality of signals to corresponding locations within said area; transmitting a location signal; receiving said location signal and measuring a difference between two properties for said location signal; comparing said difference between two properties for said location signal with a corresponding said calibration map to generate a plurality of comparison maps; combining said plurality of said comparison maps to generate a combination map; and determining said likely region, said likely region being a region within said combination map defined by a predetermined threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for displaying a region likely to include a location of an object, said region within a predefined area, said method comprising:
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generating a calibration dataset of expected properties of a location signal related to a known position of a locator device; transmitting at least one location signal; receiving said at least one location signal, said receiving said at least one location signal comprising measuring a difference between two near field properties of said at least one location signal; generating a likelihood map showing the likelihood of said location of said object as a function of position within said predefined area by comparing at least one property of said at least one location signal with said calibration dataset to determine a likelihood of said locator device being at each of a number of candidate locations within said predefined area; determining a likely region based on said likelihood map, said likely region representing a region within said likelihood map where said object is likely to be located;
said likely region encompassing a plurality of possible locations for said object; anddisplaying said likely region within a display of said area to distinguish said likely region from the remaining portion of said area. - View Dependent Claims (16)
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Specification