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First Claim
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1. A method of determining the location of a target, comprising:
- initializing a plurality of base stations to determine their relative location to each other wherein, during initializing, a first base station of the plurality of base stations sends a UWB signal to a second base station and a third base station of the plurality of base stations to determine a distance between the first base station and the second base station and a distance between the first base station and the third base station and wherein the second base station sends a UWB signal to the third base station to determine a distance between the second base station and the third base station;
measuring, at the target, the time of arrival of at least one UWB signal from each of the plurality of base stations;
calculating directly the location of the target relative to the plurality of base stations, where the plurality of base stations is at least three when a time of arrival technique is used and wherein the plurality of base stations is at least four when a time difference of arrival technique is used.
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Abstract
The present invention relates to a method of determining the location of a target. The method includes initializing a set of base stations to determine their location relative to each other. At the target, the time of arrival of at least one signal from each of the plurality of base stations Is measured. From this, the location of the target relative to the plurality of base stations may be directly calculated using a closed solution. In one embodiment, a time of arrival technique is used and in another embodiment a time difference of arrival technique is used. Preferably an ultra-wide band frequency is utilized.
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Citations
27 Claims
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1. A method of determining the location of a target, comprising:
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initializing a plurality of base stations to determine their relative location to each other wherein, during initializing, a first base station of the plurality of base stations sends a UWB signal to a second base station and a third base station of the plurality of base stations to determine a distance between the first base station and the second base station and a distance between the first base station and the third base station and wherein the second base station sends a UWB signal to the third base station to determine a distance between the second base station and the third base station; measuring, at the target, the time of arrival of at least one UWB signal from each of the plurality of base stations; calculating directly the location of the target relative to the plurality of base stations, where the plurality of base stations is at least three when a time of arrival technique is used and wherein the plurality of base stations is at least four when a time difference of arrival technique is used. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 26)
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16. A method of determining the location of a target, comprising:
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initializing a plurality of base stations to determine their relative location to each other wherein, during initializing, a first base station of the plurality of base stations sends a UWB signal to a second base station and a third base station of the plurality of base stations to determine a distance between the first base station and the second base station and a distance between the first base station and the third base station and wherein the second base station sends a UWB signal to the third base station to determine a distance between the second base station and the third base station; measuring, at the target, the time of arrival of at least one UWB signal from each of the plurality of base stations; calculating directly the location of the target relative to the plurality of base stations, where the plurality of base stations is at least three when a time of arrival technique is used and wherein the plurality of base stations is at least four when a time difference of arrival technique is used wherein, for calculating the location of the target, the plurality of base stations creates a coordinate system with the first base station being an origin location, with the second base station being located on a first axis relative to the origin location and with the third base station being located on a second axis relative to the origin location. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 27)
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25. A method of determining the location of a target, comprising:
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initializing a plurality of base stations to determine their relative location to each other wherein, during initializing, a first base station of the plurality of base stations sends a UWB signal to a second base station and a third base station of the plurality of base stations to determine a distance between the first base station and the second base station and a distance between the first base station and the third base station and wherein the second base station sends a UWB signal to the third base station to determine a distance between the second base station and the third base station; measuring, at the target, the time of arrival of at least one UWB signal from each of the plurality of base stations; calculating directly the location of the target relative to the plurality of base stations using a closed solution, where the plurality of base stations is at least three when a time of arrival technique is used and wherein the plurality of base stations is at least four when a time difference of arrival technique is used, wherein the calculating step uses a non-iterative technique to calculate the location of the target and wherein, for calculating the location of the target, the plurality of base stations creates a coordinate system with the first base station being an origin location, with the second base station being located on a first axis relative to the origin location and with the third base station being located on a second axis relative to the origin location and wherein the coordinate system is set up on an ad hoc basis and is a local system entirely based upon relative distances between the plurality of base stations, the target or both and wherein the plurality of base stations are non-line-of-sight relative to each other and wherein; i. each of the base stations is a mobile base station; ii. the measuring and calculating steps are repeated at least 200 times a sec; iii. the calculating step yields a location of the target with a resolution between about 0.01 and about 1.0 meter.
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Specification